WELL, ON COLLEGE CAMPUSES IT WAS ELIMINATED BY THE OBAMA ADMINISTRATION: Whatever happened to the presumption of innocence?

The great liberal English barrister John Mortimer called this presumption the “golden thread” running through any progressive idea of justice. And it’s a thread that is being weakened in the febrile post-Weinstein climate.

It is now astonishingly easy to ruin a celebrity or near-celebrity. You can do it with a social media post. Spend five minutes writing a Facebook entry about how so-and-so in Hollywood once did something bad to you and — boom — that person is done for. You can dispatch him from polite society with a press of a button on your cellphone.

Some big hitters, including Weinsten, Toback and Kevin Spacey, have been brought low by numerous similar accusations. Few would doubt that these men deserve the “predator” brand, or lament the fact that they likely won’t find work in Hollywood ever again. Spacey is being erased from Ridley Scott’s “All The Money In The World,” replaced with Christopher Plummer like an out-of-favor commissar airbrushed from a group photo with Stalin. But not all accusations are equally well-substantiated.

In a few hours, George Takei went from a hero of the liberal Twittersphere to a “pervert,” from cultural icon to the object of chortling and finger-pointing. His downfall was authored by a single accuser regarding a single incident in 1981. That someone can be so tarnished on the basis of an allegation older than half of the people on Earth is astounding. In the U.K., the situation is darker still.

Well, I don’t think George ever said a nice word about the presumption of innocence in sex-abuse cases before. Maybe he appreciates it now.