Senate Republican leaders tried to dig in their heels Monday on Brett Kavanaugh’s nomination to the Supreme Court, projecting defiance on calls to slow down the confirmation process for the embattled nominee after a woman, Christine Blasey Ford, said he sexually assaulted her decades ago.

But reality quickly caught up with those leaders when a small but influential group of GOP senators demanded that Kavanaugh and Ford both testify under oath before lawmakers vote on his nomination.

The Senate Judiciary Committee later announced that Kavanaugh and Ford will do just that in a public hearing next Monday.

“As I said earlier, anyone who comes forward as Dr. Ford has done deserves to be heard,” Sen. Chuck Grassley (R-IA), the committee’s chairman, said in a statement, adding that his staff reached out to Ford and spoke with Kavanaugh earlier Monday. “However, to provide ample transparency, we will hold a public hearing Monday to give these recent allegations a full airing.”

The announcement ended a day of back-door maneuvering by Republican leaders trying to avoid a public hearing featuring Kavanaugh and Ford, who went public with her sexual-assault allegation in an interview with The Washington Post on Sunday.

GOP leaders’ calculus appeared to shift by the hour. Senate Majority Whip John Cornyn (R-TX), a senior member of the judiciary committee, told reporters Monday morning that a hearing was out of the question, calling it a “show trial.” But after a meeting with Sen. Susan Collins (R-ME) in her office, it became clear that his position was no longer untenable. Collins pushed Cornyn on the idea of putting Kavanaugh and Ford under oath, according to a source familiar with their discussion. Collins indicated that under-oath testimony was essential in order for the confirmation process to move forward, causing Cornyn to reverse course.

“I have said that in order for me to assess the credibility of these allegations that I want to have both individuals come before the Senate Judiciary Committee and testify under oath,” Collins told reporters Monday afternoon.

Asked whether she believed Ford’s account of the alleged assault, Collins said she did not know enough about Ford or her claims to make a decision yet. She added that Kavanaugh “emphatically” denied the accusations when she spoke with him Friday by phone.

“That’s why, having the opportunity to observe her being questioned, read a transcript, a deposition, and make that kind of assessment is so important,” she said. “Obviously if Judge Kavanaugh has lied about what happened, that would be disqualifying.”

She was soon joined by Sen. Lisa Murkowski (R-AK), who told reporters during a brisk walk through the basement of the Capitol that “they need to have both of them under oath” before proceeding with the confirmation process.

Monday’s saga underscored both Collins’ and Murkowski’s influential roles in the confirmation process. But it isn’t just Murkowski and Collins—the only pro-choice Republicans in the Senate—who hold the cards on Kavanaugh’s fate.

Sen. Jeff Flake (R-AZ), whose support for Kavanaugh was believed to be solid, indicated on Monday that next week’s hearing will weigh heavily on his vote for or against the nominee. He said he told Republican leaders that he would vote against Kavanaugh if Ford was not given the opportunity to tell her side of the story.

“Obviously these are serious charges,” Flake, who sits on the judiciary committee, told reporters. “And if they're true, I think they're disqualifying.”

Fence-sitting Democrats from red states, among them Sens. Joe Donnelly (IN) and Heidi Heitkamp (ND), also called for the vote on his nomination be be postponed until the claims are fully vetted. That development put Kavanaugh’s confirmation further in doubt, and it pushed GOP leaders to do whatever possible on Monday in order to hold their caucus together. If that meant honoring a handful of requests for a public hearing, so be it, they reasoned.

Raj Shah, a White House spokesman, said Kavanaugh “looks forward to a hearing where he can clear his name of this false allegation.”

The allegations roiled the confirmation process just days before the judiciary committee had been set to vote to advance Kavanaugh’s nomination to the full Senate.

Kavanaugh’s allies on the right are, thus far, sticking with him. The Judicial Crisis Network, a pro-Kavanaugh conservative group, announced on Monday that it was buying $1.5 million worth of ads aimed at defending Kavanaugh against Ford’s accusations.

A spokesman for Americans for Prosperity, a Koch-backed group that has already spent millions on the effort to get Kavanaugh on the bench, said while the allegations need to be taken seriously, the organization still supports him. The spokesman added that they “will continue follow the judiciary committee’s lead as it evaluates the allegations.”

The anti-Kavanaugh forces on the left are deploying new resources, too. Demand Justice, a liberal judicial advocacy group, said it was placing a $700,000 ad buy targeting Collins and Murkowski in Maine and Alaska, respectively, in addition to Sen. Dean Heller (R-NV), who is believed to be the most vulnerable Senate Republican ahead of the midterm elections.

NARAL Pro-Choice America announced a new digital ad targeting Heller and Collins, calling on both to vote “no” in light of the new allegations.

Many Republicans, meanwhile, accused Democrats of using the issue to smear Kavanaugh, noting that Sen. Dianne Feinstein (D-CA) received a letter from Ford, who initially wished to remain anonymous, in late July.

“I think the Democrats have kept this pretty close to their vest for a while,” Sen. Mike Rounds (R-SD) said in an interview. “Most certainly, there is a political tactic involved in it. But whether or not it is an accurate depiction of what happened, we don’t know.”

Sen. Tim Scott (R-SC), meanwhile, said he would only reconsider his support for Kavanaugh if “there was something definitive that comes out of” the hearing.