Democrats appear to have enough votes to filibuster the confirmation of Neil Gorsuch to the U.S. Supreme Court under the existing procedures of the Senate. So now the question is whether the Republicans have enough votes to “go nuclear” and change those procedures, essentially wiping out the ability of a minority party to filibuster a Supreme Court pick.

Republican Senate leaders, according to party officials, are laying out a path to put Gorsuch on the court this week, no matter what Democrats do. Republicans had wanted to do it in two votes — the vote on “cloture,” the term for ending debate or a filibuster, on Thursday, and — if they got at least 60 yes votes — moving to an up-or-down vote on Friday.

But Democrats aren’t expected to allow Gorsuch’s confirmation this way. Already, 44 Democratic-leaning senators have said they will not support cloture. So if the initial cloture vote fails on Thursday, Senate Majority Leader Mitch McConnell is expected to call for a vote that would change Senate procedure and require only 51 votes for the nomination of a Supreme Court justice to proceed, instead of 60. These changes to Senate procedure can be done by a simple majority vote.

If the Senate takes this path, there would be four votes: the initial cloture; the vote on the rule change; the cloture vote under this new rule, and then the vote on Gorsuch. There could be more — McConnell could hold more than one vote on the initial cloture in an attempt to get Democrats to back down from the filibuster and to avoid the rule change, which is controversial even among Republicans.

Under this process, the votes on cloture and the various rules around it are expected on Thursday, with a formal vote on Gorsuch’s confirmation on Friday.

But the Gorsuch confirmation could still all fall apart. Since Vice President Mike Pence can cast a tie-breaking vote, Republicans need at least 50 of their 52 members to support changing the rules for Supreme Court nominees. The GOP can afford only two defections. Three would scuttle everything.

So far, no Senate Republican has said that he or she will oppose the rule change. But Maine’s Susan Collins has expressed wariness about the move, and both she and Alaska’s Lisa Murkowski have voted against the GOP on high-profile issues this year, such as the confirmation of Betsy DeVos to be the secretary of education.

But even if Collins and Murkowski oppose the rule change, it is hard to see where Democrats find a third vote.

According to FiveThirtyEight’s Trump Score, the GOP members who vote against the president’s position most often are, in order: Collins, Kentucky’s Rand Paul, Murkowski, Tennessee’s Bob Corker and Arizona’s John McCain.

Corker and McCain, in their public comments, sound as if they will join with McConnell if necessary, as does South Carolina’s Lindsey Graham, a frequent Trump critic. Paul has not indicated that he will break from party lines on the issue.

Only one Republican, Nevada’s Dean Heller, is up for re-election next year in a state that Hillary Clinton won in 2016. He also seems very likely to take his party’s position.

“There is an overwhelming consensus from Nevadans: It’s time to put Judge Neil Gorsuch on the Supreme Court,” Heller wrote in an op-ed published on Monday in the Reno Gazette-Journal. “I agree and fully support him, and I’ll work to see that Judge Gorsuch is confirmed to serve on our nation’s highest court.”

As with the health care process in the House last month, watch the timeline. McConnell has repeatedly said that Gorsuch will be confirmed this Friday. If he pushes back that timeline, it suggests the Republican leader does not have 50 votes (plus Pence) for the rule change. Paul Ryan, McConnell’s counterpart in the House, scheduled a vote on the American Health Care Act on a Thursday, delayed it to a Friday and then pulled the bill altogether. Will McConnell be more successful?