The US Senate has narrowly advanced President Donald Trump's Supreme Court nominee Brett Kavanaugh's nomination to a final vote.
The vote - 51-49 in favour - was a test of support for the nominee who has faced sexual assault allegations from several women.
All eyes are on several swing senators for Saturday's final vote.
Judge Kavanaugh's confirmation would tilt America's highest court in favour of conservatives.
The nine-member panel has the final say on issues such as abortion, gun control and voting rules and justices are appointed for life.
Very proud of the U.S. Senate for voting “YES” to advance the nomination of Judge Brett Kavanaugh!— Donald J. Trump (@realDonaldTrump) October 5, 2018
Following Friday's vote, Mr Trump tweeted that he was "very proud".
Hundreds of protesters against Judge Kavanaugh were arrested in Washington DC, on Thursday, including comedian Amy Schumer.
After the vote, dozens also were arrested outside Republican Senator Jeff Flake's office. Mr Flake told reporters that unless "something big" changes, he will vote to confirm Judge Kavanaugh.
The "cloture" vote activated a 30-hour period of discussions in the Senate, which will be followed by the final simple majority vote in the next 24 hours.
Republicans have a 51-49 majority in the Senate. But two key swing senators voted against their party colleagues: Republican Lisa Murkowski and Democrat Joe Manchin.
Mr Manchin, of West Virginia, represents a traditionally Republican state that Mr Trump won by a landslide. The self-described "most centrist Democrat" is also up for re-election this year.
Ms Murkowski of Alaska, a state that also voted pro-Trump in 2016, has been undecided on Judge Kavanaugh throughout the hearings.
She has been lobbied by sexual assault survivors to vote against the judge and represents a state with the highest sex crime rate by far in America, according to FBI data.
Despite deciding against the nominee on Friday, she told reporters afterwards she has still not made up her mind on the confirmation vote, according to Reuters news agency.
Another key Republican senator, Susan Collins, a moderate from Maine, voted in favour of Judge Kavanaugh on Friday.
She said would announce later in the day whether she would support him in the final ballot.
Given that Republicans have a razor-thin margin of control in the Senate, the party can potentially only afford another defection if it wants to confirm Judge Kavanaugh to the Supreme Court - assuming the two swing senators vote the same in the next 24 hours.
Complicating matters, the office of Republican Steve Daines said he was planning to attend his daughter's wedding in Montana on Saturday. On Friday morning, he was reported to be arranging travel back to Washington DC for the final vote.
The judge has maintained he would be a neutral justice in a Wall Street Journal editorial titled, "I am an independent, impartial judge".
Addressing his angry testimony to the Senate Judiciary Committee, where he branded the allegations against him an "orchestrated political hit", he wrote: "I know that my tone was sharp, and I said a few things I should not have said."
Hundreds arrested in Supreme Court protest
Comedian Amy Schumer and model Emily Ratajkowski were among 302 people held for demonstrating against the nominee.
They protested after an FBI report which Republicans say exonerates him of sexual assault claims, with Democrats complaining it is too limited.
The first test vote on the nominee is due in a few hours.
The likelihood of Judge Kavanaugh winning a full Senate vote on Saturday appeared to increase after two Republicans whose backing will be essential gave a positive account of the FBI inquiry.
Thousands of demonstrators marched through the nation's capital yesterday, starting at the appeals court where Judge Kavanaugh currently presides.
They converged on Capitol Hill and held a rally outside the Supreme Court, chanting: "Kavanaugh has got to go!"
Police rounded the protesters up in a Senate office building after they sat down and refused to budge.
There was another protest in front of Trump Tower in New York City.