The 5th Circuit Court of Appeals’ 2-1 decision in New Orleans Monday to block President Barack Obama’s executive action on immigration sets the stage for another year — this one an election year — of high-stakes political battles over what to do about the country’s estimated 11.5 million undocumented migrants.

The White House responded quickly Tuesday, announcing an appeal of the ruling, but it could be mid-summer or even early 2017 — after Obama leaves office — before the Supreme Court hands down a decision in a case impacting the legal status of an estimated 5 million people.

Border security and immigration was already the centerpiece of Republican presidential front-runner Donald Trump’s campaign — “They’ve got to go” — but Monday’s court ruling puts more pressure on Republicans and Democrats, from the presidential contest down to the 435 House seats up for grabs next fall, to weigh in on the issue, especially on the campaign stump.

On Monday, before the ruling was announced, Sen. Bernie Sanders, campaigning for the Democratic presidential nomination in Las Vegas, promised to expand on Obama’s executive actions and vowed in a statement on his immigration plans that he would “not wait around for Congress to act.”

Sanders’ pledge follows a similar commitment from Hillary Clinton, as Democrats increasingly embrace the administration’s efforts to protect immigrants from deportation, especially those who have grown up in the United States or at least have established residency.

But in the Republican presidential field, candidates have followed Trump’s lead, moving to the right on immigration.

Even Sen. Marco Rubio, a key architect of 2013’s failed immigration overhaul in the Senate, has shifted on Deferred Action for Childhood Arrivals (DACA), the Obama program at the center of Monday’s court ruling. After calling DACA, which protects the so-called DREAMers (immigrants brought to the country as children) from deportation, an “important program” that can’t be “terminated from minute to minute,” the Florida Republican said in New Hampshire last week that “DACA is going to end … it cannot be the permanent policy of the United States.”

Rubio has been tagged as “pro-amnesty” by Trump, who vaulted to the top of the GOP field earlier this year by promising to secure the nation’s southern border with a wall that “Mexico’s going to pay for.”

Rubio and Trump, along with six other members of the GOP presidential field square off later Tuesday in Milwaukee, Wisconsin, in a two-hour debate focused on jobs, taxes and the economy. But the 5th Circuit ruling is likely to come up as well.

In Washington, new House Speaker Paul D. Ryan, R-Wisc., has already said a comprehensive immigration bill is off the table for 2016, telling “Meet the Press,” that “the president has proven himself untrustworthy on this issue … he tried to unilaterally rewrite the law himself.”

After seeing GOP primary voters punish lawmakers, including ousted Majority Leader Eric Cantor, who had been accused of being soft on immigration, most Washington Republicans are now content to blame the immigration stalemate on the White House while attempting to block the president’s executive action.

On Capitol Hill, Republicans are already warning the Obama administration to honor the court rulings preventing the Department of Homeland Security from implementing the expansion of DACA and a related program, Deferred Action for Parental Accountability (DAPA).

In a letter to the DHS chief last week, Iowa Sen. Chuck Grassley, joined by eight Senate Judiciary Committee colleagues, including David Vitter of Louisiana, Orrin Hatch and Mike Lee of Utah, John Cornyn and Ted Cruz of Texas, Jeff Sessions of Alabama, David Perdue of Georgia and Thom Tillis of North Carolina, expressed concerns that the administration was moving forward with a plan to expand the issuing of “employment authorization documents.”

The letter cites a memo on a U.S. Citizenship and Immigration Services website that suggests authorizing the work documents would “address the needs of some of the intended deferred action population.”

Such action, the senators contend, would amount to “yet another illegal ‘executive action’ that would not only directly contravene the will of Congress, but could also directly violate the injunction … ordered by the District Court for the Southern District of Texas in February.” (The Texas court’s injunction was upheld by the 5th Circuit).

Immigration activists took solace Tuesday in the administration’s quick action on an appeal, with some arguing a midsummer ruling by the Supreme Court against the president could hand Democrats the White House — and possibly more — by energizing millions of Latino voters just months ahead of the election.

Senate Minority Leaders Harry Reid, D-Nev., tweeted: “The Republican Party has neglected the lessons of the 2012 elections … and plunged over a cliff following the lead of Trump and Carson.”