Updated on November 10 at 12:08 p.m.

The U.S. Fifth Circuit Court of Appeals blocked a series of President Obama’s executive orders on immigration on Monday night, frustrating the administration’s efforts to shield millions of undocumented immigrants from deportation and delivering a major setback to a core policy initiative of the president’s second-term agenda.* The Justice Department said on Tuesday morning that it would appeal the ruling to the U.S. Supreme Court.

A three-judge panel ruled against the Obama administration on a 2-1 vote in Texas v. United States, upholding a lower court’s injunction against two programs. Obama created one of the programs, called Deferred Action for Parents of Americans, or DAPA, and expanded another, called Deferred Action for Childhood Arrivals, or DACA in a unilateral effort to reshape the U.S. immigration system after the 2014 midterm elections. Texas and 25 other states sued the United States soon thereafter, in an attempt to halt the executive actions.

Since the Constitution grants exclusive power over immigration law to the federal government, the states’ lawsuit might seem quixotic. To circumvent this, Texas and the other states contend that by granting deferred action to an estimated five million undocumented immigrants, the Obama administration’s executive actions force the states to either provide services to them or change their state laws to avoid doing so. Texas, the only state whose standing was explicitly recognized by the court, specifically argued that the immigrants’ “lawful presence” would require the state to provide them with “state-subsidized driver’s licenses”and unemployment insurance.

The Obama administration argues that the changes are well within the executive branch’s discretionary power to enforce existing immigration law. But conservative opponents counter that the executive actions are an unconstitutional usurpation of Congress’s power to write American laws. President Obama announced his policy change last November after considerable pressure from immigration-reform activists and Dreamers and in response to the defeat of comprehensive immigration reform in Congress.

In their decision, two judges sided with the states and the lower court in Texas, citing both the impact on Texas and the breadth of the Obama administration's changes as reasons to uphold the injunction. “At its core, this case is about the Secretary’s decision to change the immigration classification of millions of illegal aliens on a class-wide basis,” wrote Judge Jerry Smith in his majority opinion.

The administration’s interpretation of the Immigration and Naturalization Act, Smith wrote, would effectively vest the Secretary of Homeland Security with the power “to grant lawful presence and work authorization to any illegal alien in the United States—an untenable position in light of the INA’s intricate system of immigration classifications and employment eligibility.” In other words, Smith wrote, “the INA flatly does not permit the reclassification of millions of illegal aliens as lawfully present and thereby make them newly eligible for a host of federal and state benefits, including work authorization.”

In her dissent, the third judge, Carolyn King, counseled judicial restraint in what she framed as a policy dispute instead of a legal one. “Because the DAPA Memorandum contains only guidelines for the exercise of prosecutorial discretion and does not itself confer any benefits to DAPA recipients, I would deem this case non-justiciable,” she wrote. “The policy decisions at issue in this case are best resolved not by judicial fiat, but via the political process.”

King then dives into a lengthy, point-by-point rebuttal of the majority’s interpretation of Texas’s standing to challenge the executive actions, their assertion that the creation of DAPA violated the Administrative Procedure Act, and their other conclusions about the case. Her colleagues, in an unusual step, praised a dissent that strenuously criticized them. “Our dedicated colleague has penned a careful dissent, with which we largely but respectfully disagree,” the other two judges said in a footnote. “It is well-researched, however, and bears a careful read.” She did not reciprocate their praise. “I have a firm and definite conviction that a mistake has been made,” King concluded.

The legal saga does not end there. On Tuesday, the Department of Justice announced it would seek further review from the U.S. Supreme Court. In June, my colleague David Graham wrote about some activists’ hopes that a Supreme Court showdown could make immigration reform the central issue of the 2016 elections.

Advocates hope that such a decision would make candidates of both parties, but particularly Republicans, take a stand on a specific immigration question. Rather than simply being able to say that they support comprehensive immigration reform—a vague statement—they will be asked what their views are on a clear legal matter, noted Clarissa Martínez-De-Castro, deputy vice president of the National Council of La Raza. The issue plays in down-ballot elections, too. There are Senate elections in several states with large Latino populations that are expected to be close, including Illinois, Florida, Nevada, and Colorado.

To get the case before the Court this term will require some alacrity from the Justice Department. As South Texas College of Law professor Josh Blackman noted, the Obama administration is under a tight deadline this month to ensure the case is decided during the last full Supreme Court term of his presidency.

[Texas’s] brief in opposition must be filed 30 days after the case is “placed on the docket.” Therefore, if the [Obama administration’s] cert petition is filed anytime between now and November 20 or so, Texas’s brief in opposition would be filed on or before December 22, and the petition could be distributed for the January 8 conference.

The only wild card is if Texas either (a) waives the brief in opposition, forcing the Court to order them to file one, and thus stretching the clock or (b) requests an extension, pushing us past the January 8 conference. But in all likelihood, this case will be argued the last week in April or the first week in May of 2016, with a decision in June 2016.

That assumes that the justices would accept the case if given the opportunity—a strong possibility, but a far from certain conclusion. If the Supreme Court declines to hear the case, the lower court's preliminary injunction would stand until the case’s final resolution, which could come under a new president.

* The headline of this article originally stated that the court had ruled the Obama administration's actions unconstitutional. We regret the error.