*This is the sixth post in a series on Adam Cox and Cristina Rodríguez’s book, The President and Immigration Law. For earlier posts in the series, click here.

Here are the basic facts on the ground: Roughly eleven million people are living in the U.S. without legal permission, half of them having been here for ten years or more. The deportation system is capable of handling only a tiny fraction of those millions. At least for those who avoid arrest for serious crimes, deportation is seemingly a result of bad luck, aggressive enforcement officers, or shifting currents in immigration policy. 

In their illuminating book on the presidential role in immigration law, Adam Cox and Cristina Rodríguez provide a riveting history of immigration law and a vivid picture of where things stand today. They show that, over the past century or more, presidents have played an outsized role in setting policy—sometimes with little guidance from Congress, sometimes against Congress’s apparent wishes. In recent years, we have seen Obama’s efforts to regularize the status of some undocumented immigrants in his DACA “Dreamers” program, as well as Trump’s efforts to increase deportations and undo Obama’s policies. This pivotal presidential role, Cox and Rodríguez argue, is indispensable and legally defensible under current law. It is only in the Epilogue that a darker note appears, when they acknowledge that the present system remains deeply troubling.

At present, Congress seems incapable of either providing a pathway to permanent status for settled immigrants or the wherewithal to deport millions of them. Staunch immigration opponents themselves seem to lack the stomach for a massive deportation program. Even our most vehemently anti-immigration president, Donald Trump, never asked Congress for the resources to identify and round up ten thousand people a day for about three years, which is what it would take to remove the current undocumented population. On the other hand, there is bitter opposition to regularizing the status of undocumented long-term residents. Cox and Rodríguez themselves propose far-reaching immigration reforms in their Epilogue while admitting that a fundamental change in immigration politics would be needed to enact their proposals.

Among its faults, the current system is at odds with the rule of law. The rule of law requires that government decisions deeply impacting the lives of individuals be based on a clear lawmaking process, not the discretion of executive officers. It also requires that the consequences of individual actions be predictable and clear, and that the legal system give people basic security in their ability to live their lives. No legal system can fully satisfy these aspirations, but immigration law falls dramatically short. Since any one of millions of people could be deported, none enjoy full security in their lives. As an operational matter, selection of individuals for deportation is determined by the executive branch, either at the retail level by immigration officers or wholesale through presidential policies. The statutes created by Congress tag millions of people as possible targets for deportation but fail to create workable rules for determining who actually gets deported.

It’s hard to imagine that anyone is happy with the current situation. Still, no fundamental change is in sight. Presidents can modify the systems in significant ways, but they are powerless either to grant millions of people permanent status or remove them from the country.

Courts are supposed to be guardians of the rule of law, but their power to change the system is also quite limited. In terms of the substance of immigration law, Congress has extraordinarily broad constitutional power to decide who can enter or remain in the United States. In recent Supreme Court opinions, Justices have given clear signs that they may be willing to strike down laws that fail to provide clear standards to govern executive decision making. The basic problem in immigration law, however, is not that the statutes themselves are too vague but that such vast discretion is required at the enforcement stage. Yet Supreme Court precedents protect rather than inhibit prosecutorial discretion.

Even if the Court were willing to entertain a major change in constitutional doctrine, the idea that the Court would strike down huge swaths of immigration law seems fanciful. The Court might also take a more lenient attitude in interpreting immigration statutes. While that might be desirable, it would also amount to tinkering around the edges.

Given the restrictions within which courts must operate, their ability to strengthen rule-of-law norms in immigration law is limited. Still, while waiting for the political system to institute basic changes of one kind or another, courts can take at least modest steps to reduce the arbitrary nature of the system.

The Supreme Court has taken some noteworthy steps in that direction. One aspect of this effort has been to limit the role that state governments can play in setting or enforcing immigration policy. In Plyler v. Doe, the Court prevented Texas from taking punitive action against undocumented children by excluding them from the school system. Given the realities of the immigration system, the Texas system would either have helped create a permanent underclass of illiterate migrants or pushed families with children into other states, adding to the chaos of immigration policy. Similarly, in Arizona v. United States, the Court rebuffed Arizona’s effort to take it upon itself to start enforcing federal immigration law. The Court found it unacceptable that “the State would have the power to bring criminal charges against individuals for violating a federal law even in circumstances where federal officials in charge of the comprehensive scheme determine that prosecution would frustrate federal policies.” A ruling in favor of Arizona would simply have increased the chaos by adding a layer of state enforcement discretion on top of the existing layer of federal discretion.

More recently, in Department of Homeland Security v. Regents of the University of California, the Court put a modest brake on the policy gyrations caused by shifting administrations. Obama’s DACA program provided temporary relief from deportation and granted work authorization for certain immigrants who had come to the United States as children. Trump’s Attorney General issued an opinion stating that the work authorizations were unlawful. The Department of Homeland Security then repealed the entire DACA program based solely on the Attorney General’s opinion. The Court held that the repeal was arbitrary and capricious because it was not supported by a reasoned explanation. The reasoning in the Attorney General’s opinion did not cover DACA’s deportation relief, only the work authorization. DHS failed to consider the option of repealing only the work authorization. Moreover, during the time DACA had already been in effect, participants in the program had arranged their lives in reliance on the program. While DHS was free to view this reliance interest as outweighed by other factors, it was not free to ignore it altogether.

These cases reflect a realistic understanding of the role of discretion in the immigration system and of the need to regularize the exercise of discretion where possible. The cases represent at least a small step forward in terms of supporting rule-of-law values in the enforcement system. While it’s true that courts have only limited power to redress immigration law’s rule-of-law deficits, even modest improvements are better than none.

Cox and Rodríguez make a convincing case for presidential action as a way of making the exercise of enforcement discretion more transparent and accountable than the independent decisions of thousands of enforcement officers. The Supreme Court has supported the effort to temper the arbitrariness of the system by excluding states from immigration enforcement and by requiring the president’s subordinates to give reasoned explanations for their policy decisions. At best, the system remains deeply unsatisfactory. The problem is not just that the system is either too draconian or too lax, depending on one’s view of immigration policy. It is also that immigration law, in practice, deviates so far from our norms about how policy should be made and how serious sanctions should be imposed on individuals. That should be a grave concern to all of us, regardless of our policy positions on immigration.

Daniel Farber is the Sho Sato Professor of Law at the University of California, Berkeley.