Updated at 4:41 p.m. ET

Brett Kavanaugh's nomination to the Supreme Court cleared a key procedural hurdle in the Senate on Friday, and his confirmation now seems all but certain, after a key swing vote, Sen. Susan Collins, R-Maine, declared her support in a speech on the Senate floor.

Moments after Collins completed her remarks, Sen. Joe Manchin, D-W.Va., announced in a statement that he too will support the nomination when it comes up for a final vote.

That final vote is expected as soon as Saturday.

In a much anticipated speech, Collins said that she believed that Christine Blasey Ford, who accused Kavanaugh of sexually assaulting her when they were both teenagers more than 30 years ago, was a survivor of sexual assault. Still, Collins said, the allegations "fail to meet the 'more likely than not' standard," and "I do not believe that these charges can fairly prevent Judge Kavanaugh from serving on the court."

Earlier Friday Collins was part of the majority that voted 51-49 to end debate.

President Trump tweeted after the procedural vote that he was "very proud" of the Senate for taking the critical step.

One Democrat, Manchin, voted with Republicans to end debate and move the nomination forward. One Republican, Sen. Lisa Murkowski of Alaska, voted with Democrats against ending debate.

In a speech leading up to the vote, Judiciary Committee Chairman Sen. Chuck Grassley, R-Iowa, said "the resistance is located right here on Capitol Hill" and urged his colleagues to "say no to mob rule" by voting to confirm Kavanaugh.

The top Democrat on the panel, Sen. Dianne Feinstein of California, said Republicans have "largely chosen to ignore the testimony" of Ford.

Murkowski and Collins sat quietly and undisturbed at their adjacent desks as a clerk called the roll.

They sat near the aisle separating senators from both parties — an almost symbolic placement that reflected how the two moderate Republicans were considering crossing the aisle to join with Democratic colleagues to oppose Kavanaugh.

Midway through the vote, as stoic, stone-faced senators sat speechless around them, Collins and Murkowski began an animated conversation in hushed tones. Both nodded eagerly in agreement with the other.

But when all the votes were cast, ultimately Murkowski voted no and Collins voted yes. It was a surprise to Grassley, who told reporters he didn't realize the Alaska Republican would vote no until she cast her vote.

Trump, in a tweet Friday morning, criticized what he termed "the very rude elevator screamers," who he said are "paid professionals only looking to make Senators look bad!" Without evidence, he alleged that the protesters, several of whom said they have been sexual assault victims, were "paid by [financier George] Soros and others."

Senators had one day to review a confidential supplemental background check into Kavanaugh's behavior in the early- to mid-1980s when he was in high school and college. The closely guarded collection of interviews is celebrated by Republican leaders as concrete proof that Kavanaugh did not harass or abuse women. Democrats say the interviews, which they originally requested, are incomplete and inconclusive.

The FBI report did little to alleviate a bitter partisan fight over Kavanaugh's nomination. Senate Majority Leader Mitch McConnell, R-Ky., announced Thursday that the Senate would proceed anyway with the Friday procedural vote.

"What we know for sure is the FBI report did not corroborate any of the allegations against Judge Kavanaugh," McConnell said. "The second thing we know for sure is that there's no way anything we did would satisfy the Democrats."

Kavanaugh took an unusual step to boost his nomination Thursday evening, writing an op-ed in The Wall Street Journal expressing regret for the heated tone of his testimony before the Senate Judiciary Committee last week, including comments decrying Democratic attacks that were seen by some wavering senators as too partisan.

"I was very emotional last Thursday, more so than I have ever been. I might have been too emotional at times. I know that my tone was sharp, and I said a few things I should not have said," Kavanaugh wrote.

The White House defended Kavanaugh's demeanor during the hearings.

"Any human being who has been falsely accused of a range of things including gang rape has a right to be upset, has a right to be angry, and that's what we saw last week," said White House spokesperson Kerri Kupec during an interview with Morning Edition.

McConnell received the 51 votes needed to clear the procedural hurdle on Friday. Republicans have enough votes to ensure Kavanaugh's nomination in the vote expected Saturday, now that Collins and Manchin have announced their intention to support the judge. Sen. Jeff Flake, R-Ariz., is a reportedly a yes on the nomination, barring a major development. And Murkowski's vote is uncertain but she sided with Democrats Friday in the key procedural vote and opposed ending debate on the nomination.

Collins, Murkowski and Flake spent hours in a secure room in the basement of the Capitol on Thursday reviewing the roughly 45 pages of FBI interviews. Collins and Flake both said the investigation was thorough.

Flake forced Republicans to launch the additional investigation last week after a tense negotiation with Senate Judiciary Committee Democrats. Flake spent a large portion of the afternoon reviewing the FBI work and said he saw no new evidence to corroborate any of the claims against Kavanaugh, which Flake had previously indicated would mean he will vote to confirm.

Democrats saw something very different in the report. Several criticized Republicans for limiting the FBI investigation to just nine interviews. They said the process ignored many potential witnesses, including Ford.

The FBI also apparently did not interview Kavanaugh.

Senate Minority Leader Chuck Schumer, D-N.Y., said those issues raised serious doubts about Kavanaugh and his qualifications.

"Judge Kavanaugh stated at his hearing that the individuals at the incident involving Dr. Ford refuted her version of events," Schumer said Thursday. "From their own public statements, we knew that to be false, and nothing in this report changes that."

Similar concerns moved Sen. Heidi Heitkamp, D-N.D., to announce Thursday that she would oppose Kavanaugh. Heitkamp is one of the most vulnerable Democrats on the ballot in November and has seen her poll numbers slip in recent weeks. She's running for re-election in a state that Trump won in 2016 by more than 35 points.

Heitkamp said she was troubled by Kavanaugh's aggressive appearance before the Senate Judiciary Committee and the message his confirmation would send to women and girls across the country.

"When considering a lifetime appointment to Supreme Court, we must evaluate the totality of the circumstances and record before us," Heitkamp said in a statement. "In addition to the concerns about his past conduct, last Thursday's hearing called into question Judge Kavanaugh's current temperament, honesty, and impartiality."

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