The fate of millions of undocumented immigrants will soon be decided by the Supreme Court in United States v. Texas . This landmark case tests the legality of the Obama administration’s immigration program known as Deferred Action for Parents of Americans (DAPA), which would grant temporary relief from removal and trigger the opportunity for work authorization for approximately 40% of the nation’s undocumented population. Currently on hold by a Fifth Circuit injunction , a threshold and potentially dispositive issue in the case is whether Texas has Article III standing to challenge DAPA in the first place.

The litigation commenced when a consortium of states sought judicial review of DAPA’s legality before the program went into effect—or, what we refer to as “ex ante” review. That puts the states in the position of plaintiffs, which is why they must demonstrate Article III standing. From the outset of the case, the federal administration has insisted that Texas lacks standing. Indeed, it is quite possible that nobody has standing to challenge DAPA. Perhaps for that reason, several justices inquired during oral argument about possible alternatives the states might have to judicially challenge DAPA if the Court rejected Texas’s standing. One alternative proffered by Solicitor General Verrilli is that Texas could craft a policy to deny driver’s licenses to DAPA beneficiaries. Then, if sued, that state could challenge the legality of DAPA in a defensive posture—what we refer to as “ex post” judicial review. So reconceived, judicial review of the states’ challenges to the executive enforcement program is less a question of ‘yes’ or ‘no’ than it is a question of ‘how’ or ‘when’.

Here, we pick up where the thought experiment left off at oral argument. And, to that end, we frame the analysis around the following three lines of inquiry:

— First, what is required to make ex post judicial review available in this case and others?

— Second, what ways are ex ante and ex post review different, both practically and legally?

— Third, in situations where states wishing to challenge executive action ex ante may do so in the posture of a defendant ex post, what constitutional and normative values, if any, are served or undermined by these alternative paths to judicial review?

As unpacked further below, these questions give rise to many more. In broaching this new terrain, we set out to situate the ex ante/ex post alternatives in relation to each other, and within larger discussions of federalism, separation of powers, and “immigration exceptionalism.” Our preliminary view is that arguments drawn from the ex ante/ex post frame potentially cut both ways. Fundamentally, the ex ante and ex post alternatives are not equivalents. Both routes to state-sponsored judicial review of federal executive action carry concerns, but they are not the same concerns. Thus, when considered in juxtaposition, the ex ante/ex post alternatives yield a number of prescriptive tradeoffs, over which reasonable minds will surely differ.

The Availability of Ex Post Judicial Review

Ex ante judicial review is the standard route to a judicial decision on the merits: a plaintiff sues in court to directly challenge a governmental action. Texas’s judicial challenge of DAPA is such a case. By contrast, ex post review involves an indirect challenge to government action, with states in the posture of a defendant, yet raising some or all of the same merits objections.

As applied to the DAPA controversy, the ex post alternative is contingent on at least three things. First, a state must create a policy that singles out DAPA beneficiaries for exclusion from some state program or benefit, such as driver’s licenses. That contingency should not be taken for granted; politics could complicate or stymie a state’s attempt to do so. But, for purposes of this thought experiment, assume that at least one of the 26 plaintiff states in the Texas litigation would pass such a policy, and that Texas would be that state.

Second, an individual or the federal government would have to sue to challenge the new Texas policy. For example, a hypothetical Texas policy that denied driver’s licenses to DAPA beneficiaries, but that still granted licenses to other deferred-action recipients, would likely garner a preemption and/or equal protection challenge.

Third, the state’s defense must embed legal challenges to the federal program at issue. More specifically, in this ex post posture, Texas could argue that only valid federal policies can preempt state law, and that DAPA is not a valid federal policy. As to equal protection, Texas might defend on the basis that DAPA beneficiaries are not similarly situated to other deferred-action recipients, on the theory that the former class (but not the latter) was established by unlawful executive action.

This hypothetical scenario is not difficult to imagine because it has basically happened in an analogous case. In reaction to President Obama’s announcement of a similar immigration program in 2012, Deferred Action for Childhood Arrivals (DACA), Arizona created a policy that denied driver’s licenses to that program’s beneficiaries. The Arizona policy was challenged on preemption and equal protection grounds by organizations representing DACA beneficiaries, with the federal government siding with the plaintiffs as amici.

The Efficacy and Reach of Ex Post Judicial Review

Assuming that the conditions needed to give rise to an ex post judicial challenge are met, the next set of considerations turn to some important differences in the potential remedies available, and avoidable, by the ex ante/ex post alternatives.

First, on ex post judicial review, a state can raise the same merits challenges to DAPA currently before the Court in Texas, but nothing guarantees a decision on the merits. Again, this is easy to imagine, courtesy of the above-mentioned Arizona driver’s license case, which the Ninth Circuit decided two weeks prior to oral argument in Texas. More specifically, in Arizona Dream Act Coalition v. Brewer , the Ninth Circuit held that Arizona’s policy toward DACA recipients was field preempted, effectively rendering the state’s challenges to DACA’s legality irrelevant. As to Arizona’s equal-protection defense, the court explained that the alleged illegality of DACA was not a valid basis for treating deferred-action beneficiaries differently. And, so again, the court avoided a holding on DACA’s legality vis-à-vis Arizona’s equal protection defense. The result of the Arizona Dream Act Coalition case illustrates how, in an ex post posture, a reviewing court can avoid deciding merits questions in ways that seem unavailable on ex ante review.

Apart from the foregoing, there is another potential difference between ex ante and ex post judicial review. In the former posture, a merits ruling by the Supreme Court would clearly bind the federal government. But the same result would not obviously obtain if the Court were to declare DAPA unlawful in an ex post setting. There, the remedy might be limited to the state policy at issue, even if the Court’s underlying rationale was directly linked to the federal program’s invalidity. The scope of the potential remedy is not entirely clear under existing doctrine.

Competing Values of Ex Ante vs. (Only) Ex Post Review

We now turn to our third overarching question: in situations where ex post review is a viable path to a merits decision, what values are served or undermined by disallowing states the option of suing ex ante? Here, we offer some thoughts about how arguments sounding in federalism, separation of powers, and immigration exceptionalism might be understood, or recast, through an ex ante/ex post model. We choose these analytical frames because they are the ones that have dominated the discourse and litigation surrounding DAPA to date.

Federalism

From a federalism perspective, DAPA supporters worry that ex ante state challenges of the type raised in Texas will distort the federal-state balance of power. On this account, states could sue too easily, which in turn could entail the delay of (more) federal policies simply because some state officials happen to disagree with those policies.

The premise that states would be more likely to sue ex ante, if the Court leaves open that possibility, is undoubtedly correct (and is otherwise assumed to be true for purposes of this thought experiment). But the conclusion that this would distort the federalism balance depends on how much additional ex ante litigation might ensue, in which types of cases, and most importantly, whether such litigation would skew the federal-state balance in the wrong or right direction.

For present purposes, we wish only to highlight that the relevant choice is not necessarily between judicial review and no judicial review. Rather, the choice, at least in some circumstances, is between ex ante and ex post review. If the former is foreclosed, the latter might entail states passing laws that purposely flout federal policies, likely with the hope of getting sued. For those who view that sort of state self-help as undesirable, or illegitimate, then allowing states to sue ex ante may offer the advantage of judicial review without encouraging oppositional state policymaking.

Separation of Powers

In the vernacular of separation of powers, one of Texas’s professed concerns is that a holding denying states standing may mean that nobody will have standing to challenge the executive’s alleged usurpation of legislative functions.

But, again, the availability of an ex post alternative might mitigate this concern. There may be no plaintiff with standing to sue in an ex ante posture, but that does not foreclose the possibility of judicial review. Arguably, the more viable the ex post check, the less concerning the absence of an ex ante check. Yet this reciprocity may cut both ways. Arguably, the less viable (or legitimate) the ex post check, the more troubling the lack of an ex ante check on alleged executive overreach.

Of course, in some situations, judicial review arguably should not be available at all. Indeed, portions of the federal government’s brief appear to take this position. But, as explained above, the Solicitor General’s suggestion of the ex post alternative during oral argument complicates (if not concedes) that judicial review is available, albeit by indirect means.

Immigration Exceptionalism

In closing, we flag one more consideration that may be the most important of all: Texas is an immigration case. Immigration law is famously exceptional, in the sense that the Court sometimes applies constitutional norms that depart from the mainstream. Indeed, Solicitor General Verrilli hinted at separation-of-powers exceptionality at least once during oral argument. In response to Justice Kennedy’s observation (or concern) that DAPA may effectively invert the conventional congressional-executive lawmaking model, General Verrilli said: “I don’t think it’s upside down. I think it’s different, and it’s different in recognition of the unique nature of immigration policy.”

How immigration exceptionalism can or should factor into the Article III equation, if at all, remains to be seen. Here, we only emphasize that the (sometimes) exceptional nature of immigration norms might independently affect the ex ante/ex post calculus in immigration cases, even if that calculus might register differently in other contexts.

Interestingly, however, judicial abjuration in Texas might incentivize the very state action that the federal administration suggests as an alternative to ex ante judicial review. That result seems especially curious when viewed through an immigration exceptionalism lens. If and when those oppositional state policies are tested in Court, the challengers to those state policies will insist, citing Arizona v. United States , that immigration’s special attributes leaves no room for states to depart from federal policies.

This exposes some unresolved tensions when immigration exceptionalism spills between constitutional dimensions. Separation-of-powers exceptionalism in immigration may be a reason to deny the states ex ante review; meanwhile, federalism exceptionalism may be a reason why the ex post alternative is more theoretical than real. Though we cannot say for sure, this may help to explain what Chief Justice Roberts was getting at when he posited during oral argument that Texas might be snared in a “catch-22.” For all the reasons explained above, that catch may be exactly how the system is designed to work in immigration—for better, for worse, or perhaps for better and worse.

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In sum, whether Texas has standing in United States v. Texas—and more generally, whether states can or should have standing based on the type of fiscal injury claimed in the case—prompted the Court to explore alternative avenues for judicial review. In turn, that inquiry raises underappreciated and knotty questions at the intersection of federalism and separation of powers. The immigration gloss only complicates matters. But, in order to fully engage these questions, it is crucial to first get the questions right. As some justices suggested and the Solicitor General appeared to concede, the choice between judicial review and no judicial review of executive action in Texas is a false dichotomy. Rather, the choice is between no review, ex ante review, and the possibility of ex post review, and all that each entails.

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David S. Rubenstein, Professor of Law and Director, Center for Law and Government, Washburn University School of Law.

Pratheepan Gulasekaram, Associate Professor of Law, Santa Clara University School of Law.