President Donald Trump evoked a distinctly Massachusetts historical moment Thursday morning when he angrily tweeted about a so-called “witch hunt.” 

Here's his tweet:

This is the single greatest witch hunt of a politician in American history!— Donald J. Trump (@realDonaldTrump) May 18, 2017

To which Democratic Rep. Seth Moulton replied:

As the Representative of Salem, MA, I can confirm that this is false.— Seth Moulton (@sethmoulton) May 18, 2017

And although those convicted in the Salem Witch Trials of the late 17th century weren’t politicians, historian Lori Stokes says the meaning of the expression has remained consistent.

“Back in Salem they said, ‘we have a very clear step-by-step process that we follow when we investigating witchcraft and that’s not being followed here. They’re breaking the rules, and they’re rushing these cases to trial and to execution.'” she said.

And Salem is the image of a "witch hunt" in the American imagination.

"Unlike most countries in Europe, where witch hunting and putting hundreds and thousands of people to death was the norm for about a century, we had one," she said. "And so we remember it."

But she cautioned, we now look back at the Salem Witch Trials with the benefit of hindsight.

"When we look back at Salem we say, 'well there were no such things as witches, so that was of course unjust.'"

When we’re still in the middle of it though, she said, it can be hard to tell if there’s really nothing there, or if somebody’s actually a witch.