In response to the nationwide affordable housing crisis, several states have attempted to boost construction by liberalizing zoning.1 These reforms have been frequently challenged in court,2 and plaintiffs in these cases may seek early victories in the form of preliminary injunctions.3 The Supreme Court articulated the standard four-factor test for granting preliminary injunctions in Winter v. Natural Resources Defense Council, Inc.4 However, there has been widespread confusion in lower courts on how these factors should be applied and balanced.5 Recently, in Montanans Against Irresponsible Densification, LLC v. State,6 the Montana Supreme Court overruled a Gallatin County District Court’s grant of a preliminary injunction against new modifications to single-family zoning in Montana.7 The Montana Supreme Court’s decision exemplifies a widespread practice of converting the four-factor preliminary injunction inquiry into a one-factor expedited consideration of the merits, a practice with concerning implications in the housing context. Instead, the court should have focused on directly analyzing irreparable harm, which aligns better with precedent and limits the serious impact improperly issued injunctions could have on housing construction.
In 2023, the Montana legislature passed a package of housing reforms proposed by the governor’s housing task force.8 Dubbed the “Montana Miracle,” the package contained two bills that directly modified single-family zoning in certain municipalities across the state.9 SB 32310 required municipalities with more than 5,000 residents to allow construction of duplexes, and SB 52811 required all municipalities to allow construction of accessory dwelling units (ADUs). Montanans Against Irresponsible Densification (MAID), an LLC representing homeowners in several impacted municipalities, filed suit against the state in the Gallatin County District Court, asserting a variety of claims under the federal and state constitutions and seeking a permanent injunction against the implementation of these statutes.12
The plaintiffs filed a motion for a preliminary injunction, which Judge Salvagni granted.13 He analyzed the preliminary injunction under the federal standard that Montana has adopted by statute: The movant must establish that they are “likely to suffer irreparable harm [without] preliminary relief”; that they are “likely to succeed on the merits”; that “the balance of equities tips in [their] favor”; and that a preliminary injunction “is in the public interest.”14 Judge Salvagni ruled for the plaintiffs on all four elements. The plaintiffs had established the probability of irreparable injury: If the measures were not enjoined, plaintiffs “could wake up one morning to find that, without any notice at all, a new duplex or ADU . . . [was] going up next door in their previously peaceful and well-maintained single-family neighborhood.”15 Evidence of specific, imminent construction was not necessary.16 Furthermore, Judge Salvagni stated that “[a]ny threat to the deprivation of fundamental rights” constituted “irreparable injury per se.”17 He next held that the plaintiffs had established a probability of success on the merits.18 He determined that the contracts clauses in the state and federal constitutions prohibit laws that interfere with restrictive covenants — therefore, the laws here could not displace any restrictive covenants that ban ADUs or duplexes.19 This conclusion meant that the laws would treat properties differently depending on whether or not they were subject to restrictive covenants, and Judge Salvagni held that this differential treatment also plausibly created an equal protection violation.20 He concluded his merits analysis by holding that the plaintiffs were likely to succeed on their claims related to substantive due process, public participation, and notice.21 Finally, he briefly dispatched the last factors for a preliminary injunction, determining that there were few harms to the state, significant harms to the plaintiffs, and a public interest in granting the injunction.22
The case was appealed directly to the Supreme Court of Montana, and a five-justice panel unanimously reversed.23 Writing for the panel, Justice Baker first confirmed that the Montana statute implements the federal preliminary injunction standard set out in Winter. She noted that while the prior test in Montana was disjunctive — allowing movants to prevail if any of the prior criteria were met — the current standard is conjunctive, placing the burden on movants to establish every element.24
Justice Baker then reviewed the district court’s analysis of irreparable injury, holding that the movant must allege more than a mere “possibility” of injury and that the plaintiffs had not met this standard.25 She noted that statutes enjoy a presumption of constitutionality, that not all constitutional violations create irreparable injury, and that the state constitutional rights asserted by the plaintiffs here were rights that could be validly circumscribed by the state’s police power.26 Moreover, she determined that the district court erred by not requiring plaintiffs to point to specific, imminent construction — MAID had offered only “generalized fears and supposition” about the practical and legal impact of the bills.27 Since granting a preliminary injunction on the basis of a mere “possibility” would be inconsistent with the nature of the preliminary injunction as an “extraordinary remedy,” Justice Baker held the district court had abused its discretion.28 Justice Baker then briefly addressed the balance of equities and public interest factors. She critiqued the district court’s cursory conclusion that the state would not be harmed by the delay of an injunction.29 Rather, she held that the legislative history and the proceedings of the governor’s task force evinced an “extensive deliberative process” that demonstrated a public interest in the legislation.30 Given this record, and the “thin evidence of imminent harm” to the plaintiffs, she held that the district court had abused its discretion in finding for the plaintiffs on these prongs.31 Thus, the court reversed the grant of the preliminary injunction and remanded the case while allowing the laws to take effect.32 On remand, Judge Salvagni held for the plaintiffs on their contracts clause claim, but held for the state on the merits of most of the other constitutional claims.33
The Montana Supreme Court’s reasoning in this case exemplifies a widespread practice in preliminary injunction decisions of grounding the inquiry in the merits, a practice with particularly problematic implications for new laws attempting to increase housing supply. Though the opinion did not explicitly analyze the merits, its determinations on each of the other prongs hinged on the merits of the underlying constitutional disputes. Reducing the test to expedited merits consideration heightens the risk of error, and the costs of such errors are particularly high in the housing context. Instead, the court should have considered which types of alleged injuries are genuinely irreparable, an inquiry that is faithful to precedent, consistent with the purpose of the preliminary injunction, and more effective at minimizing the cost of error.
While the court’s opinion facially centered irreparable injury, its analysis of this prong depended on its assumptions about the merits. The plaintiffs had alleged both practical harms, like future construction and changes to neighborhood character, as well as the legal harms of their violated rights.34 The district court, citing precedents on free speech and privacy, held that the “deprivation of fundamental rights” creates a “per se” irreparable injury.35 The Montana Supreme Court could have overruled this holding independently of the constitutional merits by distinguishing the irreparability of the rights asserted — for example, by explaining why precedents holding that violations of free speech rights are irreparable do not apply to contracts clause claims. Such a distinction would address the irreparability prong regardless of the merits of the claims. While the opinion did state that “not every constitutional infringement may support a finding of irreparable harm,” it did not explicitly state whether the violations alleged here are irreparable, or, if not, on what basis they could be distinguished from the cited speech and privacy precedents.36 Instead, it observed that the state constitutional rights asserted could be validly “limited by the State’s police power.”37 But this distinction does not speak to irreparability — rights like free speech can also be validly circumscribed by the police power.38 The state’s latitude in limiting a right does not imply that the right is reparable when violated, but rather that the right has not, in fact, been violated. Such a determination about whether rights have been violated is a quintessential question on the merits and is wholly independent of the irreparability that the opinion itself described as central.
The Montana Supreme Court’s analysis of the public interest and the balance of equities prongs also necessarily depended on the merits. When the government is a party, precedent suggests that those prongs merge because the government represents the public interest;39 the opinion thus determined that the state’s goal of addressing the housing crisis and its “extensive deliberative process” in passing the law indicated that the state and public both had an interest in enforcing the law.40 But this analysis cannot be complete. Legislation, by definition, results from legislative process. If legislative process were sufficient to satisfy the public interest prong, then the public interest would never favor an injunction against a validly enacted statute. Ample federal precedent thus holds that there is no public interest in enforcing an invalid or unconstitutional law.41 The court’s analysis can only be squared with these precedents by reference to the merits: The injunction here is against the public interest not because it enjoins legislation that resulted from legislative process, but because of an assumption that it enjoins valid and constitutional legislation resulting from that process. That assumption, of course, is an assumption about the constitutional merits of the case.
Admittedly, courts across the country struggle to comply with precedents on preliminary injunctions without elevating the merits, particularly in cases challenging new laws on constitutional grounds. As Professor Samuel Bray has noted, courts are pulled toward the merits by doctrinal assumptions that constitutional injuries are irreparable and that the public interest and equities depend on constitutionality.42 Courts’ predictions of the merits correlate strongly with whether preliminary injunctions issue, especially when the government is a party.43 But the result is a doctrine that is inconsistent with binding Supreme Court precedent stating that the preliminary injunction is an “extraordinary remedy”44 that “does not follow as a matter of course from a plaintiff’s showing of a likelihood of success on the merits.”45
Beyond doctrine, this reduction to the merits is also bad policy because decisions about the merits rendered in advance of full briefing and a developed factual record are less likely to be accurate.46 This case illustrates the problem. The district court held that the plaintiffs were likely correct that the state and federal contracts clauses prohibited displacement of existing restrictive covenants.47 The district court also held that the difference between properties that are and are not protected by covenants likely created an equal protection violation.48 But these two conclusions cannot both be true. If laws cannot displace restrictive covenants, and laws cannot treat properties differently based on whether or not they are subject to such covenants, then no zoning law would be valid unless it were as restrictive as the most restrictive covenant in the state.49 On remand, with the benefit of full briefing, Judge Salvagni ruled against the plaintiffs on their equal protection claim, effectively resolving this tension.50 Yet his ruling at the preliminary injunction stage missed the implications of its merits analysis, and the appellate opinion did not address the problem. Such oversights are more likely on the expedited schedule that the preliminary injunction requires. Moreover, a later ruling may not resolve these issues because the injunction itself might impact the ultimate outcome. An erroneous preliminary injunction may grant one party unearned leverage for settlement negotiations.51 Psychologically, through the “lock-in” problem, judges may also feel bound to their initial determination even when further briefing changes the merits.52
The error costs of these preliminary injunctions are also particularly acute for cases challenging zoning modifications. Litigants across the country have challenged attempts by states and municipalities to relax zoning laws.53 While some plaintiffs assert state statutory claims,54 many are also asserting violations of state or federal constitutional rights.55 Under the current federal doctrine, it is easy for courts to grant injunctions near-automatically in these cases whenever they feel, without the benefit of full consideration, that the plaintiffs have the better case on the merits. Meritless preliminary injunctions are windfalls for these plaintiffs at the expense of the public. Upholding the injunction for the Montana plaintiffs would have halted new construction during litigation, but it would not have halted ongoing increases in the cost of housing. To illustrate, in Minneapolis, a similar suit was recently dismissed after over six years of litigation.56 Multiple injunctions in that case were overturned on appeal, so the law largely remained in effect during the litigation.57 Over the years, Minneapolis has been rewarded with lower rent growth than similarly situated cities.58 Minneapolis likely would have experienced significantly higher housing costs had a preliminary injunction been granted early and held in place.
In the housing context, delay itself can be fatal. Ongoing litigation impacts the ability of housing projects to attract financing,59 and these risks worsen for investors if construction can be delayed by erroneous claims of constitutional harm. Delay can even be sufficient to permanently cancel projects,60 meaning that the prospect of an eventual victory provides insufficient relief.
Given these problems, courts should both reduce the undue weight they give to direct analysis of the merits prong and avoid indirectly incorporating the merits into analyses of irreparability — but analyzing irreparability on its own terms comes with another set of challenges. How should courts assess irreparability, and how should they balance competing claims? Professor Cass Sunstein distinguishes between irreparability as “irreversibility” (the loss of options) and as “incommensurability” (the inability to accurately measure and compensate loss).61 Under both, loss of property value appears reparable: It is easily measured and can be compensated at any time. Losses related to “neighborhood character” are more complex. It is plausible that a neighborhood’s “character” can neither be accurately priced nor effectively remedied by restoration ex post. The reparability of constitutional rights is also complex. On the one hand, lost rights may be “irreversible” — in Montana, once the plaintiffs were denied their claimed right of participation, they could not regain it once a decision had been rendered. But it is not clear that rights really are “incommensurable” — courts regularly award damages as compensation for rights violations.62 Yet, as Minneapolis’s progress demonstrates, there are also irreparable costs to the injunction itself. Competing claims of irreparable injury are not easily resolved.
There are tools that could mitigate these tensions. Courts could consider cabining the scope of their preliminary injunctions to be plaintiff-protective, rather than universal.63 For zoning challenges, that could mean enjoining the law exclusively in the plaintiffs’ cities, their neighborhoods, or even near their individual properties. This solution would protect the allegedly irreparable interests asserted by the plaintiffs while minimizing equally irreparable harms to the public.64 There may also be legislative solutions to the preliminary injunction inquiry itself, particularly in the context of laws designed to promote construction. Montana’s statutory adoption of the federal standard likely raised the threshold for a preliminary injunction in comparison to the prior “disjunctive” test. However, the legislation could have gone further to explore other tests that would better align this procedural device with the substantive needs of the state.
Nationally, those substantive needs are dire. There is widespread agreement that a nationwide shortage of millions of housing units has raised costs for homeowners and renters alike65 while exacerbating larger problems like inequality and climate change.66 As fights over housing policy increasingly play out in courts, states would be well served by turning their attention to the procedural devices that will determine whether and how their legislative reforms actually translate into results for people on the ground.