WASHINGTON (AP) — Longtime friends and Republican senators Lisa Murkowski and Susan Collins displayed vastly different styles Friday, reaching opposite conclusions on the crucial question of Judge Brett Kavanaugh's nomination to the Supreme Court.

Murkowski, in her fourth term representing Alaska, quietly uttered a single word — "no" — as she turned against President Donald Trump's choice for a seat on the high court.

Collins, in her fourth term representing Maine, spoke on the Senate floor for 45 minutes explaining her support for Kavanaugh.

Collins's announcement proved decisive. Minutes after she finished speaking, West Virginia Democratic Sen. Joe Manchin said he, too, would back Kavanaugh, ensuring at least 51 "yes" votes in the Senate.

All three senators — along with Arizona Republican Jeff Flake — had been publicly undecided for weeks as they faced unrelenting pressure from both sides.

In the end, Collins and Murkowski diverged.

In a Senate speech that was disrupted by protesters before it began and met with applause from GOP senators when it ended, Collins declared, "I will vote to confirm Judge Kavanaugh."

Collins told a rapt Senate that she does not believe that sexual assault allegations against Kavanaugh rise to a level to "fairly prevent" him from serving on the high court. Kavanaugh deserves a presumption of innocence, Collins said, and allegations by Christine Blasey Ford and other women did not reach a threshold of certainty.

Murkowski chose the opposite path.

"I believe that Brett Kavanaugh is a good man. It just may be that in my view he's not the right man for the court at this time," Murkowski told reporters after voting to oppose Kavanaugh in a procedural vote Friday morning.

While she respects her colleagues' support for Kavanaugh, Murkowski said, "I also that think we're at a place where we need to think about the credibility and integrity of our institutions."

Both senators won praise from their colleagues.

"I think what Susan did today was rise to the occasion when the stakes were so high," said Sen. Lindsey Graham, R-S.C., one of Kavanaugh's most ardent supporters.

Flake said he thinks "the world" of Murkowski and said she made her own decision despite intense pressure to vote yes. "I admire her a lot," he said.

Murkowski's vote was the latest example of the independent streak she forged since overcoming a Republican primary challenge in 2010 to win a re-election as a rare write-in candidate. She was re-elected in 2016.

Murkowski has expressed unease with the sexual assault allegations lodged against Kavanaugh, which he denies. She has faced pressure from home state Alaskans, including Native Alaskan women, who have described the scourge of sexual assault.

Collins took pains to say she believes Ford suffered a sexual assault that "has upended her life," but said she was not convinced Kavanaugh was the culprit. None of the people at the high school gathering where Ford said the assault took place have corroborated her account, Collins said.

"Believe me I struggled with it for a long time," Collins said after her speech. "I found Christine Ford's testimony to be very heart-wrenching, painful and compelling. But there was a lack of corroborating evidence."

Even so, Collins said she hopes the ugly fight over Kavanaugh's confirmation will raise awareness of the pervasiveness of sexual assault. She supports the #MeToo movement, Collins said, calling it badly needed and long overdue.

Collins has never opposed a Supreme Court nominee, voting to confirm the past five justices from Republican and Democratic presidents.

Besides interviewing and talking to people who know Kavanaugh, Collins said she assembled a team of 19 attorneys to assist her in examining his judicial record. She called the appeals court judge eminently qualified, adding that his judicial philosophy is well within the mainstream.

In keeping with her deliberative style, Collins had kept mum for weeks about how she would vote.

Still, she sent signals that Kavanaugh had cleared a hurdle by reassuring her that he believed the 1973 Roe v. Wade decision on abortion rights is settled law. Democrats argue that Trump picked Kavanaugh, in part, because he is likely to vote to overturn that ruling.

Kavanaugh supporters were elated. "Sen. Collins' speech was one of the most consequential speeches in the history of the United States," gushed South Carolina's Graham. The speech "should be required viewing in every civics class in America," he added, praising Collins' detailed reasoning and patient approach.

Collins and Murkowski are the only GOP senators who support abortion rights, a crucial issue in the Kavanaugh debate. If confirmed, Kavanaugh could tip the court's balance toward conservatives for a generation.

Collins lamented a pressure campaign aimed at her and other wavering senators and said millions of dollars in "dark money" had been spent by Kavanaugh's opponents. Liberal groups have been running TV ads encouraging Collins and other senators to reject Kavanaugh.

Murkowski also rendered her decision Friday in dramatic fashion. As the clerk read names in alphabetical order on a procedural vote to move the nomination forward, all eyes were on Murkowski.

When it was her turn, Murkowski stood up, paused, and whispered "no," her voice barely audible. Then she took her seat, looking down with a stone-faced expression.

Collins, who sits next to Murkowski, leaned over and put her hand on the arm of Murkowski's chair. The two huddled in deep conversation.

Associated Press writers Mary Clare Jalonick and Juliet Linderman contributed to this story.