WASHINGTON — Judge Brett M. Kavanaugh, the front-runner to replace Justice Anthony M. Kennedy on the Supreme Court, once argued that President Bill Clinton could be impeached for lying to his staff and misleading the public, a broad definition of obstruction of justice that would be damaging if applied to President Trump in the Russia investigation.

Judge Kavanaugh’s arguments — expressed in the report of the independent counsel, Kenneth W. Starr, which he co-wrote nearly 20 years ago — have been cited in recent days by Republicans with reservations about him and have raised concerns among some people close to Mr. Trump. But Judge Kavanaugh has reconsidered some of his views since then, and there is no evidence that they have derailed his candidacy.

A federal appeals judge and onetime law clerk for Justice Kennedy, Judge Kavanaugh, 53, is one of only two or three candidates Mr. Trump is still considering for the opening on the court, people familiar with his thinking said. The others are Judge Raymond M. Kethledge of the Sixth Circuit and Judge Amy Coney Barrett of the Seventh Circuit. Mr. Trump said on Thursday that he would announce his choice at 9 p.m. Monday, a day before leaving for Europe.

“I have it down to four people, and I think of the four people, I have it down to three or two,” he told reporters on Air Force One as he flew to a rally in Montana. “I think they’re all outstanding.”