Maine GOP Sen. Susan Collins on Friday ended the suspense over whether she would back Brett Kavanaugh — announcing that she would support President Trump’s nominee for the Supreme Court, all but assuring his confirmation.

“I will vote to confirm Judge Kavanaugh,” Collins said, concluding a dramatic, roughly 45-minute speech on the Senate floor after explaining her reasons for her decision, which included his assurance to her that Roe v. Wade was settled law.

Kavanaugh, she said, was far more mainstream in his judicial philosophy than his critics have maintained, noting that he frequently votes with fellow appeals court Judge Merrick Garland, President Barack Obama’s nominee to the high court — who was never given a hearing by the GOP Senate leadership.

Addressing the sexual assault charges lodged against him, she stressed the importance of the ideal that an American is considered innocent until proven guilty.

“When our passions are most inflamed, fairness is most in jeopardy,” she said, calling some of the allegations against Kavanaugh “outlandish.”

She also said she found testimony by Dr. Christine Blasey Ford compelling and sincere — but stressed that it was uncorroborated by others.

And she praised the #MeToo movement as real and relevant — and called for zero tolerance for sexual assault and misconduct.

Earlier, she slammed the confirmation process.

“Today, we have come to the conclusion of a confirmation process that has become so dysfunctional that it looks more like a caricature of a gutter-level political campaign than a solemn occasion,” she said as chanting protesters disrupted the proceeding, shouting, “Vote no!”

She noted that she had voted for nominees put forward by Presidents George W. Bush, Obama and Trump, and that the president in power never influenced her vote.

Minutes after her announcement, Democratic Sen. Joe Manchin of West Virginia, who had also been on the fence, tweeted: “I will vote to support Supreme Court nominee Judge Brett Kavanaugh.”

Senate Majority Leader Mitch McConnell (R-Ky.) had said earlier that after lunch with the Maine senator and other top GOP senators, he was confident that Collins — unlike Alaska Republican Lisa Murkowski, who voted against ending the debate on the nomination — would toe the party line.

If Collins votes no and other senators’ votes remain the same, the vote would be tied 50-50 and Vice President Mike Pence would surely cast the deciding vote in favor of the nominee.

As the end of the vote neared earlier Friday, Collins, who sits next to Murkowski, leaned over and put her hand on the arm of Murkowski’s chair as the two huddled in deep conversation.

Collins and Murkowski are the only GOP senators who support abortion rights, a crucial issue in the debate over Kavanaugh’s nomination.

If confirmed, Kavanaugh could tip the court’s balance toward conservatives for a generation.

Collins said Kavanaugh assured her during a private meeting that Roe v. Wade, the ruling that established national abortion rights, was settled law.