The Supreme Court has never answered that question, and it is among the most important at Kavanaugh's hearing since Trump could face a subpoena in special counsel Robert Mueller's Russian Federation investigation.
Trump, could face a subpoena in the case, and the top Democrat on the committee, Sen.
Harris' question appeared to puzzle the Supreme Court nominee, who paused for long periods before asking the California senator if she wanted to know whether he spoke with a specific person at the firm about Mueller.
"That's a hypothetical question".
What has Kavanaugh said about stare decisis?
"I'm not going to answer hypothetical questions of that sort", Kavanaugh said, responding to questions from Sen.
"I've been very aggressive in hiring the best" clerks, Kavanaugh said, and understanding that "the best include women".
Mueller is also probing whether members of Trump's campaign, including his son Donald Trump Jr. and son-in-law Jared Kushner, colluded with the Kremlin.
Chuck Grassley addresses document debate in Supreme Court nomination. But Kavanaugh's paper trail goes beyond that, as he also worked in the George W. Bush White House and for independent counsel Kenneth Starr during the investigation of President Bill Clinton.
In perhaps the first moment of the confirmation hearing that was mostly about the 2020 Democratic presidential primary, Harris bore down on Kavanaugh. On Thursday, he released emails from Kavanaugh's time in the White House marked "committee confidential" in a move he acknowledged was against Senate rules. He made clear earlier Wednesday that he believes "no one is above the law".
Trump has repeatedly criticized the federal judiciary when he doesn't get his way in a case, such as when the courts struck down his initial Muslim travel bans.
Blumenthal finished his 30-minute block of questioning by saying that Kavanaugh's decisions on the U.S. Court of Appeals for the District of Columbia have put him at odds with gun control.More news: Salisbury attack suspects ‘are members of Russian military intelligence’
"That takes some backbone". Kavanaugh again said he had never taken a position on those issues, though he did write in a 1998 article that impeachment may be the only way to hold a president accountable while in office.
Kavanaugh said, "The first thing that makes a good judge is independence, not being swayed by political or public pressure".
He also said he would respect past Supreme Court rulings.
"Respect for precedent is important. A judge must interpret the Constitution as written, informed by history and tradition and precedent", he said.
Capitol Police on Tuesday removed 61 protesters opposed to Kavanaugh from the room - often forcibly dragging them as they defiantly screamed about reproductive rights and other issues - and charged them with disorderly conduct. Kavanaugh considered the judge a friend and mentor and Kozinski testified at Kavanaugh's 2006 confirmation hearing to be an appellate judge.
If confirmed by the Senate, Kavanaugh is seen as likely to tilt the nation's highest judicial body even further to the right.
Senate Democrats have vowed a fierce fight.
Barring a surprise, Republicans appear on track to confirm Kavanaugh to the Supreme Court, perhaps in time for the first day of the new term, October 1, little more than a month before congressional elections.
Asked about court precedents, the importance of previously settled cases including the landmark 1973 Roe v. Wade decision that ensures access to abortion, Kavanaugh said, "Respect for precedent is important".
Trump picked Kavanaugh, 53, to replace Justice Anthony Kennedy, who announced his retirement in June.
Republicans hope to confirm Kavanaugh in time for the first day of the new Supreme Court term, October 1.