This post has been updated with the latest news.

What was once a nearly sure thing — confirming conservative-leaning Judge Brett M. Kavanaugh to the Supreme Court — is now in question after a woman accused him of sexually assaulting her decades ago while the two were in high school.

Kavanaugh denies the allegation; Christine Blasey Ford, a professor in California, stands by her story and has taken a polygraph test and shared therapy notes to corroborate it. Powerful Republicans have lined up behind Kavanaugh, including President Trump. They have set up a hearing Monday and invited both Kavanaugh and Ford to testify. Kavanaugh accepted, but Ford says she wants the FBI to investigate the claims first.

So where does that leave Kavanaugh and Republicans, who clearly want to get Kavanaugh on the court as soon as possible? A few scenarios:

Scenario 1: The Senate proceeds as normal. Republicans are facing a tight timeline to get Kavanaugh on the court before the November midterm elections, in which their majorities in Congress are on the line. With Kavanaugh, they would be able to firm up the court’s conservative lean, which would be a huge selling point to their base in what is shaping up to be a tough year for Republicans.

It’s possible Senate Republicans hold this public hearing with or without Ford and then move forward on his nomination. Even one of the Republicans most skeptical of Kavanaugh suggested late Tuesday that that would be a good idea.

But would forging ahead with Kavanaugh’s nomination come across as being insensitive to a woman alleging a serious sexual assault? Republicans have to tread carefully here. The Post’s Michael Scherer reports that before all this happened, polls showed female voters prefer Democrats to Republicans.

Scenario 2: Kavanaugh’s nomination gets paused until after the midterm elections. This is not the option Republicans want. But late Tuesday, Ford may have forced them to seriously consider it.

She said through a lawyer that she wants the FBI to investigate before she goes before a partisan Congress. Republicans might feel politically pressured to take her up on that, especially after Trump said “we should go through a process, because there shouldn’t even be a little doubt" about Kavanaugh’s nomination — an impossible standard of proof about a decades-old allegation, but one he set nonetheless.

If Republicans feel enough public pressure to at least appear as if they are investigating the matter further, Kavanaugh’s nomination could simmer on the back burner. That would be bad news for Kavanaugh, because even though he denied it, this allegation is not something he wants stewing.

From The Post’s Emma Brown, who talked to Ford:

While his friend watched, she said, Kavanaugh pinned her to a bed on her back and groped her over her clothes, grinding his body against hers and clumsily attempting to pull off her one-piece bathing suit and the clothing she wore over it. When she tried to scream, she said, he put his hand over her mouth.

It’s also bad news for Republicans. If this confirmation stalls, it could give Democrats control over the process. Right now, Democrats are heavy favorites to take back the House. In a really big blue wave, they could take back the Senate. That would bring us to the lame-duck session of the Senate late this fall, when Republicans could try to ram a nominee through in the final weeks they hold the majority.

If that doesn’t work and the seat is still vacant in a Democratic-held Senate early next year, Republicans would be on the losing side of the argument they used in 2016 to hold up President Barack Obama’s Supreme Court nominee. Could or would a Democratic Senate then demand a new nominee from Trump, or even hold that person up through the 2020 presidential election?

Scenario 3: Kavanaugh drops out. The worst-case scenario for Kavanaugh would be this, obviously. He clearly wants his nomination to go forward. He has denied the allegation and will testify under oath that it never happened. But do others convince him that this situation is just too messy for that to happen? At least in public, he has his powerful backers who don’t want to restart this whole process. “Our Plan B is the same as our Plan A: Judge Kavanaugh,” the Senate’s No. 2, John Cornyn (R-Tex.), told The Post on Tuesday.

But this last scenario is something to watch if moving forward with Kavanaugh becomes politically untenable for Senate Republicans and Trump. And right now it appears they don’t have a lot of options.