Kavanaugh’s accuser, Christine Blasey Ford, will give her account of an alleged incident in which she said Kavanaugh sexually assaulted her at a party when both of them were in high school.
Kavanaugh, who denies the allegations made by Ford and by two other women who have come forward, will also testify himself on Thursday, although he will not be in the room when Ford is speaking.
The all-male Republican majority on the Senate Judiciary Committee has hired a female lawyer with experience prosecuting sex crimes, Rachel Mitchell, to question Ford.
Democratic senators are set to ask their own questions.
A conservative appeals court judge, Kavanaugh was nominated by President Donald Trump in July and appeared to be heading toward confirmation by the Republican-controlled Senate until Ford’s allegations became public earlier this month.
Now his fate is unclear. Although Republican leaders say they want to move forward with a confirmation vote, some moderate Republicans have not yet committed to voting for him.
They include Senator Jeff Flake, who sits on the Senate Judiciary Committee that begins its hearing at 10 a.m. (1400 GMT) on Thursday.
Senate Democratic Leader Chuck Schumer and all the Judiciary Committee’s Democrats have called on Kavanaugh to withdraw in light of the allegations, and said if he does not, an FBI investigation is needed before any Senate confirmation vote.
If Kavanaugh survives what is expected to be tough questioning from Democratic senators on Thursday, the committee could vote on his nomination on Friday, with a final Senate vote early next week.
Supreme Court appointments must be confirmed by the Senate, and Trump’s fellow Republicans control the chamber by a narrow 51-49 margin, meaning Republican defections could sink his nomination.
The late controversy in Kavanaugh’s nomination process has unfolded just weeks ahead of the Nov. 6 midterm elections, in which Democrats are seeking to take control of Congress.
Trump chose Kavanaugh after the retirement of Justice Anthony Kennedy, who was a “swing” vote on the Supreme Court, a conservative who nonetheless sided with liberals in favor of abortion rights and gay rights in some key cases.
Kavanaugh’s confirmation would cement conservative control of the Supreme Court, as Trump moves to shift it and the broader federal judiciary to the right.
Blasey Ford, a psychology professor at Palo Alto University in California, has said a drunk Kavanaugh attacked her and tried to remove her clothing at a party when both were high school students in Maryland in 1982, when he was 17 years old and she was 15.
Two other women, Deborah Ramirez and Julie Swetnick, have also accused Kavanaugh of sexual misconduct and their allegations will also likely be discussed at the hearing.
Ramirez accused Kavanaugh of exposing himself during a drunken dormitory party during the 1983-84 academic year when both attended Yale University.
The latest allegations that emerged Wednesday were brought by Swetnick, who said she witnessed efforts by Kavanaugh and others to get girls so drunk at parties that they could be raped. She also said Kavanaugh was present at a 1982 party at which she was raped.
Kavanaugh has denied all of those allegations.
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