WASHINGTON — After weeks of shocking accusations, hardball politics and rowdy Capitol protests, a pair of wavering senators declared Friday they will back Brett Kavanaugh’s Supreme Court confirmation, all but guaranteeing the deeply riven Senate will elevate the conservative jurist to the nation’s highest court on Saturday.

The announcements by Republican Susan Collins of Maine and Democrat Joe Manchin of West Virginia ended most of the suspense over a political battle that has transfixed the nation — though die-hard Democrats insisted on arguing through the night to a mostly empty Senate chamber.

Some of them continued raising concerns that Kavanaugh would push the court farther to the right, including with possible sympathetic rulings for President Donald Trump, the man who nominated him. But the case against Kavanaugh had long since been taken over by allegations that he sexually abused women decades ago — accusations he emphatically denied.

In the pivotal moment Friday, Collins, perhaps the chamber’s most moderate Republican, proclaimed her support for Kavanaugh at the end of a Senate floor speech that lasted nearly 45 minutes. While she was among a handful of Republicans who helped sink Trump’s quest to obliterate President Barack Obama’s health care law last year, this time she proved instrumental in delivering a triumph to Trump.

Collins told fellow senators that Christine Blasey Ford’s dramatic testimony last week describing Kavanaugh’s alleged 1982 assault was “sincere, painful and compelling.” But she said the FBI had found no corroborating evidence from witnesses whose names Ford had provided.

“We will be ill-served in the long run if we abandon the presumption of innocence and fairness, tempting though it may be,” she said. “We must always remember that it is when passions are most inflamed that fairness is most in jeopardy.”

Those passions were on full display this week in a fight that could energize both parties’ voters in elections for control of Congress just five weeks away. The showdown drew raucous demonstrators — largely anti-Kavanaugh — to the Capitol, where they raised tensions by repeatedly confronting lawmakers despite an intensified police presence. Another 101 protesters were arrested Friday, the U.S. Capitol Police said.

It’s all expected to conclude Saturday afternoon with a final roll call almost solidly along party lines. That would mark an anticlimactic finale to a clash fought against the backdrop of the #MeToo movement and Trump’s unyielding support of the nominee, opposing forces that left Kavanaugh’s fate in doubt for weeks.

Manchin, the only remaining undeclared lawmaker, used an emailed statement to announce his support for Kavanaugh moments after Collins finished talking, making him the only Democrat supporting the nominee. Manchin faces a competitive re-election race next month in a state Trump carried in 2016 by 42 percentage points.