If Pelosi’s requirement is that the government be open for the State of the Union to proceed as planned, the Senate on Thursday will have its opportunity to make that happen. The votes will be the chamber’s first attempt to end the record-long shutdown.

Both measures would require a filibuster-proof 60 votes to advance, meaning that either seven Democrats would have to back Trump’s plan or 13 Republicans would have to support the alternative. Most Democrats have roundly condemned the president’s proposal, which contains what they consider “poison pill” provisions that would make it harder for refugees to seek and obtain asylum in the future. The Democratic measure, which has already passed the House, is more straightforward—a clean but short-term, continuing resolution with a sweetener of billions of dollars in disaster-relief money—and Republicans have been quieter in their opposition.

On Wednesday, I surveyed the offices of 23 Republican senators who frequently or occasionally cross party lines to see how they planned to vote. Of those that responded—about one-third—all indicated that they planned to back Trump’s proposal, but none definitively came out against the Democratic alternative. A spokeswoman for Senator Lisa Murkowski, for example, said the Alaska Republican supports the White House plan, but added, “She is planning to support anything that allows for a process for us to reopen the government as soon as possible, while addressing border security.” Representatives for Senators Johnny Isakson of Georgia and Mike Enzi of Wyoming said they were each studying the Democratic proposal. By Thursday morning, Senators Susan Collins of Maine and Cory Gardner of Colorado, who are up for reelection in 2020, both said they’ll vote for both the Trump and Democratic plans.

That sampling is not an indication of momentum—none explicitly endorsed the second plan either. But it suggests that Republicans are keeping their options open, raising the possibility that once the Trump plan fails, they could vote with Democrats to temporarily end the shutdown. Republican senators have harbored thinly veiled frustration with the president for the past month, ever since his abrupt decision to oppose a spending bill they voted out of the chamber, precipitating the shutdown’s start. They welcomed Trump’s recent bid to jump-start negotiations by offering limited protections for recipients of the Obama-era Deferred Action for Childhood Arrivals program, which at least gave Republicans an offer to rally around.

Yet for the president and for his party, the political pressure to end the shutdown is only increasing. Furloughed federal employees protested inside a Senate office building and outside the locked Kentucky offices of Senate Majority Leader Mitch McConnell. The rate of absences for unpaid Transportation Security Administration agents has been increasing, and The Washington Post reported that hundreds of IRS employees were skipping work because of financial hardship, jeopardizing the completion of on-time tax returns. Federal courts will soon run out of money, and FBI investigations are grinding to a halt.