WASHINGTON — In a defiant and emotional bid to rescue his Supreme Court nomination, Brett Kavanaugh on Thursday denied allegations that he sexually assaulted Christine Blasey Ford when both were high school students and angrily told Congress that Democrats were engaged in “a calculated and orchestrated political hit.”

“You have replaced ‘advice and consent’ with ‘search and destroy,” he told the Senate Judiciary Committee, referring to the Constitution’s charge to senators’ duties in confirming high officials.

He vowed to continue his effort to join the high court, to which President Donald Trump nominated him in July. Now a judge on the District of Columbia Circuit Court of Appeals, Kavanaugh seemed assured of confirmation until Ford and several other accusers emerged in recent weeks. He has denied all the accusations, but it remained unclear how the day’s dramatic testimony by Ford and Kavanaugh would affect his prospects.

“You may defeat me in the final vote, but you’ll never get me to quit, never,” he said.

In a daylong, extraordinary Senate airing of long-ago and painfully personal memories, Ford told the senators earlier that she was “100 percent” certain a drunken young Kavanaugh had pinned her to a bed, tried to remove her clothes and clapped a hand over her mouth as she tried to yell for help. A Kavanaugh friend stood by and they both laughed uproariously during the incident, which occurred in a locked bedroom at a gathering of high school friends, she testified.

In her three hours of testimony, Ford’s tone was polite but firm as she detailed her accusations but offered no major new revelations. Rachel Mitchell, a veteran sex crimes prosecutor from Arizona who asked all questions for the committee’s all-male GOP senators, seemed to elicit no significant inconsistencies in her testimony.

But as deferential and hushed as Ford’s delivery was, Kavanaugh’s was incensed and combative. He repeatedly interrupted Democratic senators’ questions, including on whether he’d support their bid for testimony by Mark Judge, the friend who Ford has claimed participated in Kavanaugh’s attack on her.