As the fate of Deputy Attorney General Rod Rosenstein hung in the balance Monday, U.S. Sen. Patrick Leahy (D-Vt.) said that firing the official overseeing the Special Counsel investigation into President Donald Trump's 2016 campaign would be "a bad mistake."

"It would be very, very damaging — both to the president and to the Republican Party because it would scream of cover-up," said Leahy, the senior-most member of the Senate Judiciary Committee.

Leahy made the remarks near the end of a day of furious speculation over whether Rosenstein would offer his resignation or Trump would fire him. His status has been uncertain since Friday, when the New York Times reported that Rosenstein had suggested in the spring of 2017 that he wear a wire to record the president and seek Trump's removal from office by invoking the 25th Amendment. The White House said Monday afternoon that Rosenstein remained at the Department of Justice, but that he was scheduled to meet with the president on Thursday.

According to Leahy, firing Rosenstein could effectively end Special Counsel Robert Mueller's probe of Russian interference in the 2016 election because Rosenstein would be replaced as acting attorney general overseeing the inquiry by Solicitor General Noel Francisco, whom Leahy referred to as "a Trump acolyte."

Still, Leahy said he was not sure that such a firing would constitute an impeachable offense, a position that U.S. Rep. Peter Welch (D-Vt.) has taken.

"I don't know," Leahy said. "By itself? I don't know. It would depend upon where Mueller was in his investigation. It'd have to be a demonstration of obstruction of justice. I'm trying to think of it as a lawyer and a prosecutor, and I don't know the answer to that."

Leahy also responded Monday to a new allegation, reported Sunday by the New Yorker, that U.S. Supreme Court nominee Brett Kavanaugh exposed himself to a woman at a college party and forced her to touch his genitals. Kavanaugh has said that the events described by classmate Deborah Ramirez did not take place.

Asked whether he believed Ramirez's account, Leahy said, "I don't know, but I do know this: It just strengthens what I've been saying. Take the time to turn this over to independent investigators who are trained in this field."

Leahy has said the same since last week when another woman, Christine Blasey Ford, alleged that Kavanaugh assaulted her at a drunken party when both were in high school — a claim the federal judge also denies.

The Vermonter criticized his Republican colleagues on the Senate Judiciary Committee for what he characterized as an unwillingness to fully investigate the allegations before voting on Kavanaugh's confirmation. "Every new allegation that comes out, the only response from the Republicans is, 'We gotta hurry up and have a vote on him,'" Leahy said. The committee is scheduled to take testimony from Kavanaugh and Ford on Thursday and is expected to hold a vote shortly thereafter.

Leahy would not say whether Kavanaugh should withdraw from consideration for the post.

"That's a decision only he can make," the senator said. "A lot of Republicans wish he would, but that's a decision only he can make."