House Democrats on Tuesday easily passed a resolution to block President Donald Trump from using a national emergency declaration to pay for his border wall, setting the table for the real drama: whether the Republican-controlled Senate will rebuke the president by approving the resolution, too.

The House voted 245 to 182 in favor of the resolution, with 13 House Republicans joining all Democrats to approve it. The measure, sponsored by Rep. Joaquin Castro (D-TX), is privileged, which means that Majority Leader Mitch McConnell (R-KY) must put it to a vote on the Senate floor within 18 days. With all 47 Senate Democrats expected to vote in favor, only four GOP senators would need to join them to ensure the resolution passes.

Three already have: Sens. Susan Collins (ME), Lisa Murkowski (AK), and Thom Tillis (NC). Several others have sharply criticized Trump’s move, but stopped short of saying how they would vote on the measure.

Even if the Senate approves the emergency-killing resolution, it’s unlikely to be more than a speed bump for the president, who has said he will veto the bill if it reaches his desk. In that event, two-thirds of both chambers of Congress would need to get on board to overrule the veto, a threshold unlikely to be reached in either chamber.

With Trump in Vietnam for a summit with North Korean dictator Kim Jong Un, his top lieutenants are on the Hill to quell any GOP revolt there. On Tuesday, Vice President Mike Pence addressed Senate Republicans’ weekly lunch to persuade them to back the president up.

Sen. Lindsey Graham (R-SC), a strong supporter of the emergency declaration, told The Daily Beast that Pence said the emergency declaration applies to a specific statute with a “limited application.” He predicted Pence’s talk may have moved some of his colleagues who are on the fence about how to vote. Politico reported, however, that Pence was met with skepticism, and that as many as 10 Republicans could defect.

Under the National Emergencies Act of 1976, the president retains broad authority to declare an emergency, which opens up special sources of funding for the executive branch. Trump is hoping to secure access to a pot of funds, estimated at $6 billion, that he could use to construct the border wall—though those funds would be diverted from other accounts, mainly for military construction and disaster relief.

For the time being, the president is using the tussle with lawmakers as his immigration foil of the month, having pledged “100 percent” last week to veto an effort by Congress to block his declaration of a national emergency.

“Nothing new on this front since [the president] commented,” White House Press Secretary Sarah Huckabee Sanders emailed The Daily Beast on Tuesday afternoon.

With or without the veto threat, however, some Trump allies and prominent immigration hardliners weren’t keeping their hopes high to begin with. Dampened enthusiasm on the right stems from anxiety among conservative activists that Trump’s emergency declaration could lay the groundwork for a Democratic administration to exploit.

“I’m worried this is going to set the precedent, because we’ve had multiple emergency declarations… since 1976, but none of them was issued after Congress refused to cooperate on some matter,” said Mark Krikorian, executive director of the Center for Immigration Studies. “What I’m afraid of is that you are going to have President Maxine Waters declare a national handgun emergency… I’m worried about the future of republican government, not so much that Trump is going to usurp the rules… but that using it in this way is going to create a harmful precedent, and that what he is going to do with that authority isn’t going to accomplish much in reducing illegal immigration, anyway.”

What happens next in Congress will have political ramifications for both sides, but the most viable avenue to actually block Trump’s declaration is through the courts. Sixteen states, all with Democratic governors, have filed a lawsuit against it that will be heard in a federal court in Oakland, California, this week.