President Trump said Monday that Democrats’ smearing of Supreme Court Justice Brett M. Kavanaugh, and their calls for his impeachment, will prompt many disgusted Democratic voters to support Republican candidates in the mid-term elections.

Before departing the White House for Florida to speak Monday at the annual convention of the International Association of Chiefs of Police, Mr. Trump argued that the rival party will end up alienating large chunks of its base before the key November elections.

“I think a lot of Democrats are going to vote Republican,” Mr. Trump told reporters at the White House. “The main base of the Democrats have shifted so far left that we’ll end up being Venezuela. I think a lot of Democrats are going to be voting Republican on Nov. 6.”

Mr. Trump, who will attend a ceremonial swearing-in of Justice Kavanaugh at the White House Monday night, said the Senate Democrats’ raising of decades-old unfounded sexual misconduct allegations against the nominee were “atrocious.”

“It was one of the most disgraceful performances I’ve ever seen — the way they really tortured him and his family,” the president said.

“Now they’re thinking about impeaching a brilliant jurist, a man that did nothing wrong, a man that was caught up in a hoax that was set up by the Democrats, using the Democrats’ lawyers. I think it’s an insult to the American public.”

The Senate confirmed Justice Kavanaugh Saturday in a vote of 50-48. Sen. Joe Manchin III of West Virginia was the lone Democrat to support the nomination.

• Gabriella Muñoz contributed to this story.