Alan Dershowitz slammed the news that former Trump campaign manager Paul Manafort was behind bars before a trial, calling the move “obnoxious to our Constitution.”

“He has never been convicted of anything. He is as innocent as you and I,” the Harvard Law School professor said in an interview on MSNBC on Friday.

Manafort’s bail, which permitted him to be out on house arrest, was revoked by a federal judge Friday because he allegedly communicated with two witnesses to lie to investigators, thereby compromising his upcoming trial set for September. Manafort, who was arrested last October and charged with money laundering, tax evasion, conspiracy, and failure to register as a foreign agent in Washington, pleaded not guilty to the new obstruction charges.

Paul Manafort JAILED: Bail revoked for alleged witness tampering https://t.co/TelhJxmix7 pic.twitter.com/rNfVGcw7dh — Conservative News (@BIZPACReview) June 15, 2018

“Let’s start with the presumption of innocence, ” Dershowitz reacted to the news on MSNBC. “He has never been convicted of anything. He is as innocent as you and I. And the idea of locking somebody up before a trial is so obnoxious to our Constitution that every civil libertarian should be up in arms. ”

The constitutional and criminal law scholar unloaded on the breach of civil liberties, arguing that jail time before being convicted is a “dangerous thing.”

What they can do if they think that he’s tampering with witnesses is they can subject him to home arrest, take away his computer … they can have all kinds of restrictions, but the idea of putting somebody in jail before they’ve been convicted is an enactment of civil liberties” he said.

What they can do if they think that he’s tampering with witnesses is they can subject him to home arrest, they can take away his computer,” he continued.

MSNBC host Chris Jansing noted that the former Trump aide had already been under house arrest.

“Fine. They can take away his telephone, they can have all kinds of restrictions,” Dershowitz responded. “But the idea of putting somebody in jail before they’ve been convicted is an anathema to civil liberties. Except today, anti-Trump civil libertarians are forgetting about civil liberties.”

Dershowitz called out the American Civil Liberties Union for remaining silent.

“The ACLU is not doing a thing to protect the civil liberties of Americans. We have to remember the presumption of innocence. Manafort walks into court as innocent as any of us. The idea that he should be locked up because the government alleges he’s done something without having to prove anything is really a very, very dangerous thing whether it’s done to Republicans or Democrats,” he said.

“And as a civil libertarian, I’m going to continue to speak up to civil liberties of people I disagree with, people I agree with,” Dershowitz added. “And I wish the ACLU were back in the game, but now the ACLU is supporting candidates running for office, they’re taking partisan views, they are dead in the water when it comes to protecting the civil liberties of Americans. That’s why I and others like me have to be out there making the case for civil liberties on a nonpartisan basis.”

President Trump took to Twitter in reaction to the “tough sentence” for his former campaign chairman.

Wow, what a tough sentence for Paul Manafort, who has represented Ronald Reagan, Bob Dole and many other top political people and campaigns. Didn’t know Manafort was the head of the Mob. What about Comey and Crooked Hillary and all of the others? Very unfair! — Donald J. Trump (@realDonaldTrump) June 15, 2018

Trump told reporters Friday that he was feeling “badly” about Manafor, but noted that he “has nothing to do with our campaign.”