"The presumption of innocence and fairness do bear on my thinking and I can not abandon them", she added, calling Mr Kavanaugh "an exemplary public servant".
With Murkowski now presumably a "no" vote, Flake's "yes" is likely a prerequisite for Kavanaugh's confirmation. She later called the cloture vote "a mistake".
It would be a cruel irony if Manchin voted for Kavanaugh and helped save his nomination while a Republican, Murkowski, voted against him, but given that he is up for reelection in a state where Trump remains popular, it is a distinct possibility.
Another key Republican senator, Susan Collins, a moderate from ME, voted in favour of Judge Kavanaugh on Friday.
Under the pairing arrangement, the senator in the duo who is present and voting - in this case Murkowski - announces that she or he has "a pair" with the senator not in attendance.
"It's a lot of work - maybe they don't want to do it", Grassley told the Wall Street Journal, NBC News and other outlets, as he headed toward the Senate floor for a speech by Sen. The Senate Judiciary Committee says the Federal Bureau of Investigation also interviewed two alleged eyewitnesses to the incident named by Ramirez and one of her college friends.
Lisa Banks, another attorney for Ford, said her client merely wanted to tell her story so that lawmakers could "make the best decision possible".
The article was published the same day the FBI made available to senators a report on its speedy investigation into sexual misconduct allegations against Kavanaugh.
That vote is expected Saturday.
US President Donald Trump nevertheless cheered the result of the cloture vote.
Republicans hold a bare 51-49 majority in the Senate.
I believe is is a good man.
Democrats don't seem to have the votes to keep Brett Kavanaugh from joining the Supreme Court, but that's not stopping them from taking to the Senate floor in a parade of speeches into the early morning against the conservative jurist. I have been wrestling to really try to know what is fair and what is right, and the truth is, that none of this has been fair.
"I believed he was going to rape me", Ford said about Kavanaugh. Jeff Flake said he could not support a full Senate vote on Kavanaugh's confirmation until a supplemental background check was conducted.