The decision by the woman, Christine Blasey Ford, came after days of uncertainty over whether she would appear at a hearing and answer questions about her accusations of sexual assault.
In the turbulent days after the firing of James B. Comey, the deputy attorney general appeared conflicted about his role and wanted to expose administration dysfunction, people around him said.
The president said he wanted to hear from Christine Blasey Ford, the accuser: “If she shows up and makes a credible showing, that’ll be very interesting.”
Three moderates had been weighing a yes vote to confirm Judge Brett M. Kavanaugh, while other Democrats hoped there would be few consequences for a no vote. The sexual assault allegation has changed calculations.
Christine Blasey Ford, who has accused Supreme Court nominee Brett M. Kavanaugh of sexual assault, has yet to confirm that she will appear at hearings on Monday.