Harvard law professor emeritus Alan Dershowitz revealed Thursday that he would “enthusiastically” support former Vice President and 2020 frontrunner Joe Biden over President Donald Trump if the two face off in the 2020 general election.

Appearing on Sirius XM radio’s The Dan Abrams Show, Dershowitz said that he’s both fond of Biden personally and a “strong supporter” of him politically. “I like Joe Biden. I’ve liked him for a long time, and I could enthusiastically support Joe Biden,” Dershowitz told host Dan Abrams.

“Over Donald Trump?” Abrams asked the veteran lawyer.

“Over Donald Trump, yeah,” Dershowitz replied.

Dershowitz then went on to criticize Biden’s closest rival, Sen. Bernie Sanders (I-VT), saying that he wasn’t certain he could “pull that lever” for the self-avowed Democratic Socialist in the general election.

“If Bernie Sanders is nominated, that would present a real dilemma for me,” he said. “I don’t think under any circumstances I could vote for a man who went to England and campaigned for a bigot and anti-Semite like Jeremy Corbyn. I don’t think I could do it. I couldn’t pull that lever.”

Dershowitz, a lifelong Democrat who endorsed 2016 Democrat nominee Hillary Clinton, has long argued it was a mistake to appoint a special counsel to investigate now-debunked collusion between the 2016 Trump campaign and Russia. Reacting to special counsel Robert Mueller’s press conference earlier this month regarding his report, Dershowitz said Mueller had revealed his “partisanship” and “not only put his thumb on the scale against President Trump — he put his elbow on the scale. And he did it improperly.”

“A prosecutor is supposed to decide whether or not there is sufficient evidence to indict. If there isn’t, he’s supposed to shut up,” he added.

In recent days, Dershowitz has appeared on cable news networks defending the president against arguments in favor of beginning impeachment proceedings. Appearing Wednesday on Fox News Channel, Dershowitz argued Congress’s ouster of the president is “not constitutionally possible.”

“If Hillary Clinton were elected president and they were trying to impeach her, I would have written a book called ‘The Case Against Impeaching Hillary Clinton.’ Congress cannot impeach President Trump because if they did, they would be putting themselves above the law,” he told host Sean Hannity. The Constitution provides criteria for impeachment: treason, bribery, high crimes and misdemeanors. Unless there is compelling evidence, impeachment is not constitutionally permissible. The president is not above the law, but neither is Congress.”

In 2018, Dershowitz authored the book The Case Against Impeaching Trump.