Harvard Law School professor Laurence Tribe, a fierce critic of President Trump, said Wednesday that former Special Counsel Robert Mueller's House Judiciary Committee hearing was a "disaster" that set back impeachment efforts.

“Much as I hate to say it, this morning’s hearing was a disaster," Tribe tweeted. "Far from breathing life into his damning report, the tired Robert Mueller sucked the life out of it. The effort to save democracy and the rule of law from this lawless president has been set back, not advanced."

DERSHOWITZ, TRIBE SPAR OVER IMPEACHMENT: YOU'D HAVE 'GONE APOPLECTIC' IF CLINTONS RECEIVED SAME TREATMENT

Tribe, who has taught at Harvard for more than five decades and has close ties to President Obama, is the author of a 2018 book, “To End a Presidency: The Power of Impeachment.” He also recently compared Trump to Adolf Hitler.

LAURENCE TRIBE TELLS CNN VIEWERS HOW TO IMPEACH PRESIDENT TRUMP: 'YOU HAVE TO SHOOT TO KILL'

In a May 2018 interview with CNN, Tribe warned viewers that if they truly want Trump impeached, they must focus on major abuses of power instead of nitpicking every minor incident.

“If you’re going to shoot him, you have to shoot to kill,” Tribe told anti-Trump host Chris Cuomo. “And that requires an overwhelming majority of a bipartisan kind. Otherwise, you’re just going to nick the guy, and make him feel empowered and vindicated.”

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Tribe later apologized for using the phrase "shoot to kill:" “In an otherwise good interview I made a terrible word choice, saying an impeachment 'bullet' can only be 'shot once' so one must 'shoot to kill,' he tweeted. "I wasn’t speaking literally, but as one who works hard to reduce gun violence this was just inexcusable. I’m very sorry,”

Tribe was once described by The New Yorker magazine as the “tenth Justice” to the Supreme Court back in 1996. However, the same publication asked "Did Laurence Tribe sell out?" in 2015 amid a series of controversies, including his representation of a coal company challenging Environmental Protection Agency regulations.