Legal Borderlands and Imperial Legacies: A Response to Maggie Blackhawk’s The Constitution of American Colonialism

What are the borderlands? In her brilliant and sweeping exploration of the “constitution of American colonialism,”¹ Professor Maggie Blackhawk references the borderlands dozens of times.² She ultimately looks to the borderlands for constitutional salvation, extracting six “principles of borderlands constitutionalism” that she urges us to reckon with as “central to our constitutional law.”³ These include principles of recognition, preservation, self-determination, territorial sovereignty, collaborative lawmaking, and nonintervention — concepts that she elaborates upon in significant detail.⁴

But borderlands are notoriously elusive. The borderlands of the United States are both everywhere (or, at least, in many places) and nowhere at once.⁵ So, when I read Blackhawk’s generative Foreward, I thought that the most useful contribution I might make by way of response would be to try to flesh out other dimensions of the borderlands, and to contemplate what might be gained from expanding on her notion of the borderlands.

In this Response, I will embark on a brief journey in search of the borderlands. In so doing, I highlight some tensions among the principles of borderlands constitutionalism, and suggest some additional challenges that inhere in any effort to invigorate these principles in the framework of the United States’s colonial constitutional law. In the first Part of this Response, I summarize key elements of Blackhawk’s Foreword and explain the role that the borderlands, and borderlands constitutionalism, play in her argument. In the second Part, I expand upon this idea of the borderlands, and offer some reflections on how an engagement with other borderland spaces and realities might advance distinct aspects of the constitutional project that Blackhawk sets out. In the third Part, I offer an analysis of immigration law that both bolsters Blackhawk’s central claim concerning the colonial legacy that animates and structures U.S. constitutional law and illustrates some of the difficulties of constitutional redemption through borderlands constitutionalism. The final Part offers some brief reflections about how we know what we know about U.S. colonialism and its continuing practical and legal legacies.

I. The Constitution of U.S. Colonialism

Blackhawk opens The Constitution of American Colonialism with a description of U.S. colonialism, past and present.⁶ She does so as part of her broader effort to do nothing less than to reconceptualize broad swaths of U.S. constitutional law. She argues that “[c]onstitutional scholars rarely discuss the problem of American colonialism at all. . . . Instead, we call the component parts of American colonialism sui generis. We banish each to its silo.”⁷ Blackhawk identifies these siloes — “federal Indian law; the law of the territories; foreign relations law; treaty law; the war powers; and the laws of naturalization, immigration, and citizenship”⁸ — and observes that these bodies of law are commonly declared “beyond our constitutional theory and left . . . to the ‘plenary power’ of the political branches to solve.”⁹ In her view, however, “the national government built a constitution of empire: a vast and intricate web of relationships between the central government and those it colonized.”¹⁰ Colonial governance is not extrinsic to, nor is it ex­ceptional within, the resulting constitutional framework. United States constitutional law has provided the legal infrastructure of U.S. colonialism, and has been interpreted and reordered to facilitate the governance of colonized spaces from the center.

Blackhawk calls upon us to reckon with the constitution of colonialism, but urges that we must not only “recognize colonialism as a distinctive struggle of fundamental practices, norms, and institutions within our society,” but also grapple with ongoing discourse within colonized spaces “around power, self-determination, sovereignty, jurisdiction, and community as a distinctive form of constitutional discourse.”¹¹ Indeed, one of the most important insights that Blackhawk provides is in her reminder that grappling with the legal legacies of colonialism should not lead to a blanket “solution” that favors the universal imposition of homogenized U.S. liberal constitutional values and frameworks on colonized people and jurisdictions. She reminds us that in the absence of a more robust framework for understanding our Constitution’s colonialism, the unthinking extensions of even the constitutional frameworks that have emerged to respond to particular aspects of the racially violent past in the United States would have the ironic effect of further disempowering some colonized people.¹²

Using Haaland v. Brackeen¹³ as one example, Blackhawk admits that advocates (including herself) who had filed amicus briefs in the Supreme Court defending the Indian Child Welfare Act (ICWA) contended that they were not advocating on behalf of a “racial” group notwithstanding the many ways that Native communities have been racialized.¹⁴ To do otherwise would send the analysis of ICWA into the Court’s deracinated, ahistorical, colorblind equal protection analysis,¹⁵ where it might very well meet the same fate as affirmative action¹⁶ and voluntary desegregation efforts¹⁷ — a fate that may soon await the Voting Rights Act as well.¹⁸ As Blackhawk explains,¹⁹ the Constitution’s antidiscrimination principles have previously been (mis)used to upend efforts to promote the self-determination of Native Hawaiians in the case of Rice v. Cayetano.²⁰ In a world where the Fourteenth Amendment cannot be read to remediate the historical racial wrongs of slavery, the danger that decontextualized principles of antidiscrimination and equal protection may continue to be used to further the ends of colonial power remains strong.

Similarly, principles of federalism, which have at times delivered protections for individual rights, have also been used (including quite recently) to advance the cause of colonial control. Blackhawk writes of the Supreme Court’s recent decision in Oklahoma v. Castro-Huerta²¹ in which the Court deployed an expansive understanding of state criminal law jurisdiction in Native lands at the expense of recognizing tribal sovereignty in these places:The United States Constitution provides the several states with a constitutional right to impose their criminal law on colonized lands — to police, and subject to criminal sanctions, the loved ones, neighbors, and children of colonized peoples. But the Constitution also limits the United States from empowering the people it colonizes to self-govern, even simply to protect their families against crime, because United States citizens who are non-Indians could then be subject to the laws and governments of colonized peoples.²²

Nor have liberal constitutional principles come to the aid of colonized people in Puerto Rico. Blackhawk makes this plain in her analysis of recent cases like Puerto Rico v. Sanchez Valle,²³ Financial Oversight and Management Board for Puerto Rico v. Aurelius Investment, LLC,²⁴ and United States v. Vaello Madero,²⁵ for which:The most generous interpretation of these recent opinions is that the Supreme Court draws from borderlands constitutional principles implicitly and justifies the lesser harm of a particular case to avoid a more problematic general rule. This interpretation could be true. However, when the Court was faced with the choice to embrace the lesser harm of the particular case and craft a general rule that preserved borderlands principles[,] . . . it chose the general rule that furthered the colonial project.²⁶

What is required then, is not a blind extension of the liberal constitutional principles that were forged in the fires of colonialism and then used as a tool for its extension and maintenance. Instead, Blackhawk urges, we need to make a genuine and sincere attempt to understand the “constitution of American colonialism,”²⁷ and to search out “distinctive constitutional solutions”²⁸ to the complex inequities, misappropriations, and disenfranchisements of colonialism’s historical legacy and ongoing damage. Rather than simply extending or universalizing constitutional doctrines as they have been designed to address certain problems (and to obscure others), we must grapple with historical specificities and engage the legal vocabularies and technologies adopted in the borderlands by people seeking to preserve their autonomy and self-governance in the face of U.S. colonialism.²⁹

To undertake this task, Blackhawk admits that she has, at best, a partial roadmap. She modestly styles her epic tour de force as a conversation starter — a broad introduction to questions that she posits at the end of the piece: [H]ow do we incorporate and give voice as a constitutional matter to those members subjected to a distinctive and exceptional constitutionalism — subject to its power without any of its protections? That is, how do we affirmatively engage with the constitutional questions that we may have lost to the erasure of American colonialism?³⁰

These are great questions and hard ones, and if Blackhawk has no definitive answers, it shouldn’t be surprising to anyone that I do not have them either. But Blackhawk suggests that our search for answers must start at the borderlands, and so I will start there as well.

II. The Borderlands

As we seek to reconstruct a constitutional analysis that contends with the reality and harms of colonialism, Blackhawk’s recommendation is that we look to the law of the borderlands. Elaborating pluralistic notions of what the borderlands are and what they mean might therefore enrich and complicate Blackhawk’s constitutional project. Blackhawk defines the “borderlands” early in her article:They are domains and peoples over which the United States has extended its jurisdiction unilaterally, often unlawfully and violently, on the grounds that the peoples within those borderlands require civilization before they achieve self-government. Paradoxically, borderlands are spaces of both subordination and empowerment. They are areas where “universal” rules of liberal constitutionalism apply selectively or not at all to “savages.” But they are also spaces of legal and constitutional pluralism that allow colonized peoples some powers to govern and innovate. Borderlands are where permanent “strangers” to the United States Constitution and their worldviews remain, denaturalizing the seemingly stable borders of empires and nations.³¹

Though I was unaware of the fact during my own childhood,³² Indigenous people in the Americas have long used the notion of the borderland to understand and contest control over space and their own bodies. As Blackhawk’s Foreword makes clear, Indian Country is filled with borderland spaces — sites of colonization, yes, but also of imaginative legal resistance and a resulting legal pluralism that can serve as a guide to possible reconfigurations of our constitutional understanding.³³ Native nations have their own borders, and the borderlands are therefore far more ubiquitous within U.S. territorial space than Euro-American maps allow.

Nor are these the only borderlands with which Blackhawk is concerned. The outlying U.S. territories are also borderlands³⁴ and figure prominently in her analysis. Some historical territories have been folded into the United States as states, in a series of processes that reified racial hierarchy and sought to entrench white supremacy.³⁵ Some spaces remain in territorial status to this day, part of a vast island-archipelago of U.S. empire.³⁶

But there are other borderlands — spaces that are not analyzed in Blackhawk’s Foreword and that fall outside of her definition because not all parts of these borderlands are easily defined as spaces where “the United States has extended its jurisdiction.”³⁷ When I think of borderlands, the first image for me is the place where I was born and raised — in El Paso, Texas, which sits on the northern side of the United States’s most analyzed geopolitical border. Gloria Anzaldúa described the U.S.-Mexico borderlands as:[U]na herida abierta where the Third World grates against the first and bleeds. And before a scab forms it hemorrhages again, the lifeblood of two worlds merging to form a third country — a border culture. Borders are set up to define the places that are safe and unsafe, to distinguish us from them. A border is a dividing line, a narrow strip along a steep edge. A borderland is a vague and undetermined place created by the emotional residue of an unnatural boundary. It is in a constant state of transition. The prohibited and forbidden are its inhabitants. Los atravesados live here: the squint-eyed, the perverse, the queer, the troublesome, the mongrel, the mulato, the half-breed, the half dead; in short, those who cross over, pass over, or go through the confines of the “normal.”³⁸

Anzaldúa’s book posits that “borders are set up . . . to distinguish us from them.”³⁹ The geopolitical divisions created by these territorial borders undergird the maintenance of an unequal global order that arises out of colonial history.⁴⁰ Thus, the borderlands at the physical intersection of nations are also sites where colonial constitutionalism is enacted.

Such spaces can be violent. In recent years, the U.S.-Mexico border — long home to an extensive⁴¹ (if sometimes hapless⁴²) control apparatus — has been further militarized in a series of military-styled “operations,” from the federal Border Patrol’s Hold the Line and Gatekeeper in the 1990s⁴³ to Governor Greg Abbott’s Operation Lone Star in the present.⁴⁴ This borderland is the site of a significant armed presence: the FBI, the Border Patrol, the Army, the Air Force, ICE, and other DHS agents are all present, as are armed agents of the State of Texas, the various municipalities of the region, the Mexican government, and, of course, the armed free agents on both sides of the borderline in the summer of 2023 on concertina wire and throughout the borderlands.⁴⁵

Anzaldúa’s description of her homeland as a “thin edge of barbwire”⁴⁶ gained new resonance as children wounded themselves on barbed wire in the summer of 2023 near the deceptively cheerful-looking balloons bedecked with wire that are floating⁴⁷ — sometimes on the Mexican side of the Rio Bravo/Grande⁴⁸ — at the behest of Texas’s governor. Litigation over the floating border barrier initially resulted in a federal district court order requiring Texas to remove the barrier on the grounds that it sat in the navigable waters of the United States over which the federal government has control, and upon which states cannot create obstructions.⁴⁹ The Fifth Circuit Court of Appeals later reversed the injunction, allowing the barrier to remain in place pending further litigation, but providing no reasoning for its decision.⁵⁰

Anzaldúa’s borderland exists within a particular (if fuzzy-edged) space situated at the intersection of two specific nations. But her description of the borderlands captures the reality that, like borders themselves, borderlands are not naturally occurring, but arise out of bordering processes.⁵¹ Like the borders they surround, borderlands are omnipresent and come into sharp relief wherever differences can be policed. They are metaphysical as well as physical. As Blackhawk makes clear, borderland spaces are generative.⁵² Anzaldúa reminds us that they are also sites of transgression, and therefore invite various forms of border patrolling designed to keep people in their place.⁵³

Blackhawk is attentive to the diversity of borderland spaces, and does the important service of highlighting how the solutions that might facilitate the greater political and legal autonomy of one borderland space might be a poor fit for another.⁵⁴ Her analysis focuses primarily on often-invisible borders of colonized spaces subject to the formal legal jurisdiction of the United States — Indian Country, the lands of Native nations, and island territories.⁵⁵ Though she begins by noting that the plenary power doctrine also makes its home in immigration law, the resulting immigration jurisprudence is not a focus of her work.⁵⁶ But immigration law is clearly designed to regulate borderland spaces, and has contributed to the constitution of U.S. colonialism. So in the Part that follows, I’ll briefly sketch out how we might extend Blackhawk’s project in the context of immigration law.

III. Immigration Law and U.S. Colonialism

The visible doctrinal thread that connects immigration law with the law of the territories and Indian law is the plenary power doctrine. Immigration law, one of the central legal domains in which the plenary power doctrine developed, often falls away in scholarly efforts to tether it to other legal manifestations of U.S. colonialism.⁵⁷ But if, as Blackhawk argues, “American colonialism” is the concept that unites the distinct legal siloes of the plenary power doctrine,⁵⁸ then understanding the development and functioning of plenary power in the domain of immigration law is a necessary part of the broader, connective conversation that Blackhawk has prompted.

Blackhawk rejects the notion that the plenary power doctrine is a doctrine — and not just because, as others (including, notably, immigration law scholars) have pointed out, other explanations can be found for the seemingly exceptional judicial tolerance of invidious discrimination in these decisions.⁵⁹ For Blackhawk, the problem is more fundamental — consigning issues to the plenary power of the political branches constitutes not a doctrine of constitutional law, “but the absence of constitutional discourse.”⁶⁰ She contends that matters grouped under the broad heading of plenary power are more accurately understood as a doctrinal “effort to fill the void left by the racialized hierarchy that many used to justify American colonialism and shield us from the difficult constitutional conversations that remain across the seemingly disparate, but ultimately connected ‘external’ constitutional fields.”⁶¹

But the development of immigration law suggests that plenary power in U.S. constitutional cases is not just an “absence” of constitutional discourse that avoids directly confronting racial legacies. It is also a substantial, if malleable, doctrinal vessel — one that has been forged from other sources of law, but that can be detached from the original source materials, including when that source material becomes less effective in service of the colonial project.⁶² In fact, we can see this pretty clearly in the relationship between international law and immigration law plenary power.

The Constitution does not grant immigration powers to the federal government expressly. Unlike the Territories Clause, or the Indian Commerce Clause, which govern other areas of the U.S. colonial constitution, there is no text to point to when it comes to federal power over immigration.⁶³ Though nineteenth-century jurists sometimes leaned on Congress’s power to regulate commerce and naturalization, and its power to declare war, none of these inherently require a federally consolidated immigration power, or any power to restrict individuals’ movements across borders.⁶⁴ Perhaps the absence of clear constitutional text on the subject explains why the Supreme Court cited no authority of either domestic or international law when it stated in 1889:That the government of the United States, through the action of the legislative department, can exclude aliens from its territory is a proposition which we do not think open to controversy. Jurisdiction over its own territory to that extent is an incident of every independent nation. It is a part of its independence.⁶⁵

Many of the tenets of liberal theory that undergirded the U.S. Constitution at the Founding “become incoherent if one suspends the premise of free movement.”⁶⁶ By and large, however, international law by the late nineteenth century did support the Court’s assertion, as is evident in its ruling a few short years later in Fong Yue Ting v. United States.⁶⁷ There, the Court drew heavily on international law to justify the conclusion that the federal government’s right to expel noncitizens present in the United States was as “absolute” as its right to exclude.⁶⁸ How did international law develop in this way? With the growth of its empire and the abolition of slavery within it, British efforts to control the movement of its subjects across national borders became more challenging.⁶⁹ Legal scholars writing from the centers of colonial powers met this, and related, challenges by legitimating the control of movement across borders in international and domestic law. Thus, by the late nineteenth century, the U.S. Supreme Court was able to draw upon the writings of the likes of Emer de Vattel and Theodore Ortolan, contemporary international legal scholars, to conceive of the federal sovereign prerogative as absolute when it came to defining and defending external borders.⁷⁰ The Court found no role for itself to “say what the law is” in this context.⁷¹ Though the Court signaled its ability to review administrative actions for compliance with congressional legislation, it also made clear in later rulings that there was no obvious space for individual constitutional claims, even when the political branches exercised their sovereign prerogative in ways that defied existing conceptions of due process or equal protection of the law.⁷²

International law has, of course, evolved since the nineteenth century. Yet numerous scholars working in the tradition of Third World Approaches to International Law⁷³ (TWAIL) have explained how contemporary legal notions of sovereignty, and accompanying conceptions of the sovereign right to exclude, remain central to the maintenance of the power structure of the colonial order in a post-colonial world.⁷⁴ The modern passport — which allows certain bearers to permeate border barriers that are closed to others — evolved as a central component of contemporary sovereignty, and “the passport not only is a technology reflecting certain understandings of race, nation/nationality, and state but [also] was central to organizing and securing the modern definition of these categories.”⁷⁵ The result is a global immigration law regime that creates racial borders around moving bodies in ways that replicate racialized, colonial patterns of subordination.⁷⁶

Given TWAIL scholars’ dim view of contemporary international law, including its sustained justification of oppressive forms of migration control in the guise of humanitarian law,⁷⁷ it is striking to note the extent to which U.S. notions of national sovereignty are even more problematic than modern international law. When it comes to the regulation of migration, U.S. constitutional law largely remains frozen in the nineteenth century, particularly in its treatment of national sovereignty as absolutely trumping individual rights. This archaic conception of state sovereignty places the United States out of step even with other postcolonial states when it comes to recognizing the rights of migrants. State power over migrants is (at least formally) acknowledged to have some limits in international law, and in many jurisdictions around the world.⁷⁸ But under the U.S. Constitution, those limits seldom manifest. The Supreme Court has not interpreted any part of the Constitution to protect the individual rights of migrants seeking admission, independent of the grace of the political branches.⁷⁹ Nor are the Constitution’s structural allocations of power designed to protect the rights of legal outsiders. And this, too, is a legacy of colonialism.⁸⁰

Any glimmers of possibility that things might be improving on this front have been snuffed out by the current Court. In Trump v. Hawaii,⁸¹ the Court employed reasoning that bore many of the hallmarks of late-nineteenth-century immigration cases. It addressed a ban on immigration from several predominantly Muslim countries that had been enacted to effectuate a President’s express campaign promise to engage in religious discrimination at the nation’s borders.⁸² Though the Court purported to review the ban, and did not invoke the plenary power doctrine, it employed a standard so deferential that any display of religious animosity, once properly bureaucratized, would convert into a constitutional exercise of power by the political branches in the realm of border control.⁸³ The shadow of plenary power was also evident in the ways that the challenge to the entry ban had to be asserted by U.S. citizens, residents, and organizations rather than by noncitizens outside of the United States subjected to the ban.⁸⁴ Given the extant case law, developed in the heyday of the plenary power doctrine, excluded Muslims did not even have legal grounds upon which to contest their discriminatory exclusions in federal court.⁸⁵

In a very different context, but one that again shows the shadowy persistence of plenary power, the Court recently announced new limits on habeas review for immigrants in U.S. detention facilities on U.S. soil. In Department of Homeland Security v. Thuraissigiam,⁸⁶ the Court concluded that a noncitizen detained on U.S. soil had no ability to bring a federal habeas claim in U.S. courts to contest the procedural deficiencies of the asylum proceedings that had resulted in his detention.⁸⁷ The Court, in an opinion by Justice Alito, reasoned that “[h]abeas has traditionally been a means to secure release from unlawful detention, but respondent invokes the writ to achieve an entirely different end, namely, to obtain additional administrative review of his asylum claim and ultimately to obtain authorization to stay in this country.”⁸⁸ The fact that unlawful detention is the direct result of an unlawful proceeding does not render the claim cognizable to the Court.⁸⁹ The plenary power doctrine is not invoked here either, but the decision defends a muscular version of the sovereign prerogative to exclude — one that extinguishes all of Thuraissigiam’s legal rights.

Finally, U.S. courts have been unwilling to effectuate any limits on the power of the political branches to deport immigrant residents, including those with families, friends, workplaces, and church communities in the United States, no matter how long those immigrants have been in the country, no matter how long ago they engaged in any purportedly offensive conduct, and no matter how thin their connections to their countries of nationality.⁹⁰ This, too, makes the United States an outlier as compared to both its neighbors and to former colonial powers.⁹¹ In our system of deportation, which disproportionately targets Black and Latine migrants,⁹² the racial dimensions — and the racial violence — of plenary power are continuing features of the U.S. immigration landscape.

The free hand with which the political branches deal with those “outside” of the nation’s borders, and the Court’s complicity in blurring those borders to extinguish rights claims well within them, have wounded the borderlands. The absence of meaningful checks on borderlands federal power⁹³ has facilitated the heavy militarization of the southern border, and aggressive, racialized patterns of immigration enforcement throughout its interior.⁹⁴ It has generated countless fractured families,⁹⁵ a deadly detention archipelago that now reaches every corner of the nation,⁹⁶ and a web of surveillance.⁹⁷ And it is overwhelmingly Latine families, and often Black and Indigenous migrants, who pay the price for the violent efforts to keep the border selectively closed.⁹⁸ All of this suggests that borderlands constitutionalism might be less insistent upon reflexive reinforcement of the hard legal borders of national sovereignty, and inclined toward a legal order premised upon the realities of global interdependence, or, more boldly, a global ethic of care.⁹⁹

Put differently, a more robust integration of immigration law into the discussion of the constitution of U.S. colonialism could help us to think more deeply about the many forms of colonialism and imperialism that Blackhawk lacks the space to address in her Foreword.¹⁰⁰ Communities across the globe have seen the imposition of a U.S. legal order well beyond the territorial borders of the United States. Blackhawk discusses this phenomenon in the case of the Philippines.¹⁰¹ But we might add to this a discussion of the Panama Canal Zone;¹⁰² the interventions by the United States in Central America on behalf of the United Fruit Company;¹⁰³ and a host of interventions to prop up dictatorial regimes friendly to the United States,¹⁰⁴ to displace leaders seen by U.S. elites as antagonistic to U.S. interests,¹⁰⁵ and, purportedly, to advance democracy.¹⁰⁶ Bearing heavy scars of U.S. influence, these places, too, might be productive sites of borderlands constitutionalism.

As climate change drives people — especially from marginalized and Indigenous communities — from their homes in these spaces of imperial intervention,¹⁰⁷ those individuals and communities who are fleeing will not benefit from late-breaking respect for the territorial borders of their homelands. Some of the value their territorial borders contain is being eviscerated by global climate change, cross-border contamination, and ongoing resource extraction.¹⁰⁸

Legacies of imperialism, through which power has been exercised outside of national borders without any commensurate, accompanying acknowledgement of rights or obligations, thus create the need to search for new and creative borderland principles.¹⁰⁹ These borderland principles must acknowledge cross-border interdependence, entwinement, and obligation. They call out for more permeable borders and a global order in which individuals have much greater power to choose their homes and communities.

But how does this suggestion square with Blackhawk’s call for the acknowledgment of “territorial sovereignty” as a principle of borderlands constitutionalism?¹¹⁰ Even if there is firm adherence to “nonintervention” going forward, the interconnected nature of our globe ensures continued social and climate spillover effects across borders.¹¹¹ Blackhawk advances territorial sovereignty as a means of redressing colonial pathologies,¹¹² and in the contexts in which she proposes this, it makes sense. But in figuring out how we move beyond colonial constitutionalism, we will also need to grapple with the difficult fact that territorial control is achieved at the expense of individual bodies, and that those most likely to be excluded when borders close are those who have been devalued in the intertwined global racial and economic order.

To be clear, I am not suggesting that the bid of colonized people for territorial sovereignty is the same thing as territorial appropriation and border control in the exercise of settler-colonial power. As Professors Angela Riley and Kristen Carpenter have explained, the concept of sovereignty itself means different things for different people and nations.¹¹³ It is nevertheless important to recognize that legal principles designed to protect one group of colonized people might increase the vulnerability of others, and that the instincts that one borderland community has about justice might not always mirror those of another. Here, we might see some divergences in the principles of borderlands constitutionalism that open up between the domestic borderlands and those that take us completely outside of the formal legal jurisdiction of the United States. These may not be insurmountable chasms, but they are tensions that will need to be addressed as we delve into the challenging questions that Blackhawk raises for us.

Blackhawk’s Foreword also elegantly wrestles with the conundrum that simply “overruling” the plenary power of the political branches in the spheres of federal Indian law and the regulation of the nation’s outlying territories would not provide the people of the borderlands the recognition and autonomy that they require, nor would it ensure that equal protection of the law would extend to these borderland residents.¹¹⁴ But what would “overruling” the plenary power doctrine do in the realm of immigration law?

In some ways, the question is hard to answer because the Court has not often invoked the doctrine in recent cases, leading some to question whether it matters, or even exists, in that legal realm.¹¹⁵ But if the notion of an exceptional sovereign prerogative — one that systematically favors the choices of the federal political branches over individual rights claims — is plenary power, then it seems still to be doing a lot of work in immigration law. Overruling it would mean subjecting the exercise of federal immigration power to ordinary standards of constitutional review.¹¹⁶ At first blush, however, this approach would seem to point toward less judicial deference to the political branches when compared to the status quo, even as Blackhawk’s impulse in other borderlands contexts seems, at times, to be toward greater deference.¹¹⁷

On the other hand, judicial deference to the federal political branches’ power over immigration matters has also made space for successful rights claims cast as preemption claims.¹¹⁸ In fact, some judicial rhetoric has suggested that the flipside of preemptive federal sovereign power in the immigration sphere is unchecked state power to regulate migration.¹¹⁹ Here again, then, the way forward requires more than simply overruling plenary power. It might involve something like Blackhawk’s notion of a rational basis review informed by borderland constitutional principles.¹²⁰ Even so, the cross-cutting consequences of judicial deference to the federal political branches in the area of immigration law point to the complexity of redeeming the U.S. Constitution through borderlands constitutionalism principles. This also serves as a reminder than any attempt to develop such principles will require wrestling with the unique contexts of many borderlands, not to mention a variety of pathologies in U.S. law beyond plenary power.

IV. Concluding Thoughts on How We Know What We Know

Scholars before Blackhawk have grouped the plenary power doctrine of immigration law with that of federal Indian law and the law governing the territories, as she herself acknowledges.¹²¹ When Blackhawk posits that the previously unidentified link between these (and other) doctrinal areas is “American colonialism,”¹²² she is definitely on to something. This is an important link that has been identified before by other scholars — including those working in the Critical Race Theory tradition.¹²³ It seems important to say this now.

Since the racial justice uprisings of the summer of 2020, Critical Race Theory (CRT) has been under political assault.¹²⁴ This attack on CRT is part of a broader effort to shore up a constitutional jurisprudence framed around an exclusionary interpretation of the U.S. Constitution, and simultaneously to dismiss all discussions of structural racial inequities in U.S. laws and legal systems. Public schools across the country have been staging grounds for the resulting struggles.¹²⁵ And although it is technically true that CRT was never actually taught in almost any of these K–12 schools,¹²⁶ it is also true that CRT’s opponents were taking aim at something much broader, hoping to paint as “crazy” any critical interrogation, or depiction, of racial inequality in United States history.¹²⁷

In this Response, I briefly mentioned the incomplete and misleading history textbooks I was assigned to read in my middle school days.¹²⁸ I initially included that reference incidentally, but as I finish up the writing of this Response, it occurs to me that it relates more deeply to Blackhawk’s project, and to this Response. Despite moments of miseducation — moments that occurred at various (and, at least for me, frequent) points in time from kindergarten through law school — Blackhawk and I have had the benefit of the insights of people in our communities who have questioned the orthodoxies of exclusionary, colonial histories, and who have imagined and created more inclusive legal possibilities. Both she and I have also benefitted from the work of scholars who have modeled different ways of bringing the insights of outsiders into our legal analyses and arguments. If we are to ever have any hope of realizing Blackhawk’s deeply optimistic vision of a Constitution informed by borderland principles, then we must continue to fight for the teaching of the histories of the borderlands, and to uplift the scholars who bring those insights to bear in their legal analyses.

Epilogue

I wrote a good deal of this Response from my childhood bedroom in El Paso. On a hot summer morning, my brother took me and my two children to see some fossilized dinosaur tracks in Sunland Park, New Mexico, near the base of Mount Cristo Rey. The U.S.-Mexico border is a line in the sand a few meters to the south of where we stood, and we saw a Border Patrol vehicle bouncing across the rocky hills as we studied the dinosaur tracks, but it was far enough away from us that we could not see the faces of the agents, and they did not stop us. Soon, nothing remained of them but the tracks of their tires in the dusty road.

When we had seen the dinosaur tracks, we walked across the tire tracks and down to the banks of the Rio Grande, beckoned by a cooling breeze and the fresh bushes and grasses on the river’s edge. The vibrant greens contrasted with the desert sands and low-lying, dusty scrub all around. We stood west of the river, at a place just north of where the river bends, where it no longer separates Mexico from the United States, and instead delineates the softer border dividing New Mexico from Texas on the ancestral lands of the Ysleta del Sur Pueblo. There, in the borderlands, the river runs, unfenced and free.

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* Bruce Tyson Mitchell Professor of Law, Stanford Law School. This Response is dedicated to my students, past and present. I have learned so much from you. You help me see the world in new ways.