The White House, aiming to avert an embarrassing Senate defeat over the emergency declaration Donald Trump conjured up last month to fund his border wall, has mounted a behind-the-scenes push to keep Republicans from backing a Democratic resolution to block the president’s nuclear option. The resolution, which already passed the Democratically controlled House, is expected to be brought to the Senate floor for a vote Thursday. Four Republican defections would send the bill to Trump’s desk and force the first veto of his presidency. And with three G.O.P. senators already firmly in favor of the rebuke, the administration is scrambling to convince a handful of lawmakers uncomfortable with the president’s power grab to fall in line.

According to The Washington Post, central to the negotiations is a bill by Senator Mike Lee that would amend the 1976 National Emergencies Act to reclaim some of the authority Congress ceded to the executive branch. It’s unclear how effective Lee’s law would be, particularly as the White House seeks to defang it, but it could nevertheless provide political cover for Republicans like Thom Tillis, who have publicly expressed concern about precedent, to side with Trump. Tillis declared his opposition to Trump’s nuclear option in an op-ed last month, writing in the Post that while he supports the president’s border-security measures, he “cannot justify providing the executive with more ways to bypass Congress.” He would “vote in favor” of Representative Joaquin Castro’s resolution to block the emergency declaration, he wrote.

But Tillis is seen as malleable, and in recent days the White House has reportedly targeted him and other potential defectors, including Lamar Alexander, Rob Portman, and Pat Toomey. Tillis has already shown signs of breaking, telling reporters after a private meeting with Vice President Mike Pence on Tuesday that his negotiations with the White House are a “work in progress,” and hinting to Republicans at a lunch later that Lee’s bill could be enough to get him on board.

“There’s a lot of people being bruised and bullied,” Rand Paul, who with Susan Collins and Lisa Murkowski plans to vote for the Castro resolution, said Tuesday of the pressure campaign. “They’re being beaten up right now, so if you see anybody that’s got blood dripping out of their ear, they may be changing.”

It’s unclear if the outreach, which has also included urging from Trump on Twitter for Republicans to “get tough,” will be successful. But if Republicans do band together to defeat the resolution, it would be a solid notch in the political-win column for Trump, who appeared to be facing a humiliating rebuke. Of course, neither the House nor the Senate ever had the votes to override Trump’s inevitable veto, so the resolution never posed the kind of substantive threat to his unpopular emergency declaration as, say, California’s lawsuit. But being forced to use his veto pen by disgruntled members of his own party would be humiliating, particularly for a president obsessed with loyalty and driven by optics.

More Great Stories from Vanity Fair

— How three brothers hijacked South Africa

— The deepening mystery of Trump’s SAT scores

— The best crime show you’re not watching

— Is this Trump move an actual, real-life impeachable offense?

Looking for more? Sign up for our daily Hive newsletter and never miss a story.