Unlikely Trump defender Alan Dershowitz, the liberal Harvard law professor, has raised eyebrows in recent months. Evan Mandery of Politico explains.

“People everywhere ask what happened to him,” said Nancy Gertner, a former federal judge and lecturer at Harvard Law School who has known Dershowitz for years. “I get that from everyone who knows I know him.”

Anyone under 30 could be forgiven for seeing Dershowitz as just another talking head on Trump TV, but to Gertner and her peers, that’s not even remotely who Dershowitz is. Gen Xers may know him as a celebrity lawyer, a member of O.J. Simpson’s defense team. Baby boomers know him for clearing the socialite Claus von Bulow of poisoning his wife in the 1980s. But Dershowitz had a 20-year career before that, during which he established himself as one of the most prominent and consistent defenders of civil liberties in America.

In 1963, as a law clerk, he drafted a crucial memo for Supreme Court Justice Arthur Goldberg that led to the death penalty being ruled unconstitutional. (The ruling was later reversed.) At Harvard, he sued the university’s all-male social clubs, and though he didn’t prevail, he was ahead of his time: Harvard recently severed its ties with the clubs. His legal scholarship articulates an expansive view of freedom of speech, freedom of religion and even animal rights.

Over this storied career, Dershowitz’s public persona has remained more or less unchanged: loud, provocative, brilliant and principled, if also relentlessly self-promoting. And, until recently, his positions have been tolerated, if not always embraced, by the legal academy and universally acknowledged for their moral seriousness.

About a year ago, after Mueller’s appointment on May 17, that started to change. Around then, Dershowitz—never one to overlook a celebrity being railroaded—started getting more TV airtime for his argument that a sitting president could not be guilty of obstruction of justice. The liberal intelligentsia recoiled.