The GOP’s victory afterglow had barely faded before the first major post-election battle between the President Barack Obama and the new Republican Congress began to take shape — on the explosive issue of immigration.

Incoming Senate Majority Leader Mitch McConnell (R-KY), striking an otherwise conciliatory tone, made amply clear that Republicans will fight Obama’s planned moves to ease the threat of deportation for up to millions of migrants who are low on the priority list for removal.

“It’s like waving a red flag in front of a bull to say, ‘If you guys don’t do what I want, I’m going to do it on my own,'” McConnell said Wednesday in Louisville, declaring that if Obama follows though, “I think it poisons the well” for legislative action.

The same afternoon, Obama was equally clear he won’t back down on his promise to act on immigration “before the end of the year.” He stressed that the new Republican Congress could supersede his actions by passing immigration reform, which he said he prefers, but vowed not to wait as problems linger.

“I’ve shown a lot of patience,” he said, calling it “a commitment I’ve made.”

Congressional Republicans won’t take that lying down. The issue is a powerful one for the immigration-weary GOP base, which now feels it has a mandate to fight Obama’s plans after Republicans campaigned against them and won.

McConnell pledged to use government spending bills to rein in Obama’s immigration actions, telling TIME magazine after the election that “the way that you push back on executive overreach is through the funding process.”

While McConnell expressed wariness of allowing a government shutdown, Sen. Ted Cruz (R-TX) has called on Republicans to fight it with every weapon in their arsenal. Thickening the plot is Sen. Jeff Sessions (R-AL), who is actively working to undermining Obama’s plans on immigration, and is next in line to chair the Budget Committee. From that perch, he would have the power to set spending parameters that undermine the president’s moves.



Senate Republican leader Mitch McConnell of Kentucky holds a news conference on the day after the GOP gained enough seats to control the Senate in next year’s Congress and make McConnell majority leader, in Louisville, Ky., Wednesday, Nov. 5, 2014. (AP Photo/J. Scott Applewhite)

More broadly, the upcoming clash will draw the battle lines ahead of the 2016 presidential election. The influential Hispanic community, long clamoring for deportation relief, likely will rally to Obama’s side and attack the GOP for opposing him. GOP candidates will be torn between the tea party base and the Latinos, who carried Obama to a resounding reelection victory against Mitt Romney as he campaigned on “self-deportation” of undocumented immigrants. The wishes of the GOP base and Hispanics are vastly different and probably cannot be reconciled.

“The strategy behind the protestations of Mitch McConnell and others is clear. They want to intimidate the President into inaction,” said Frank Sharry, the executive director of the leading immigrant-rights group America’s Voice. “They know that Presidential action will reveal that GOP leaders are not in control of the party’s immigration agenda, but rather that Senator Ted Cruz (R-TX), Jeff Sessions (R-AL) and Steve King (R-IA) are. And they know that the predictable GOP overreaction to common sense steps will cement the GOP’s anti-Latino, anti-immigrant reputation heading into 2016.”

Sen. Lindsey Graham (R-SC), an author of the Senate-passed immigration bill, hinted at the GOP’s 2016 dilemma in a Wednesday appearance on CNN.

“My sense is this is a dangerous miscalculation by the president,” he said, arguing that reform should happen legislatively, not by executive action. But he cautioned that it’s “hard to see how we can win the presidency in 2016 if we’re seen as blocking immigration reform.”

This is a fight from which neither side has any intention of backing down.

House Speaker John Boehner (R-OH) has been laying the groundwork to blame Obama’s executive actions for the failure of immigration reform. Republican National Committee Chair Reince Priebus told reporters on Wednesday that “the idea of serious immigration reform is still alive,” but he accused Obama for having “continuously lied” to Hispanics about it.

Boehner and Priebus recognize that while the 2014 elections were fought in parts of the country with few Hispanic voters, Latinos are poised to play a major role in 2016 battleground states.

Obama’s comments on Wednesday suggest that, contrary to the dejected president after the 2010 midterm “shellacking,” he won’t back down after what he conceded was “obviously … a good night” for Republicans.