If the definition of insanity is doing the same thing over and over expecting different results, then Republicans lost their minds chasing the Clintons down rabbit holes years ago.

They spent the 1990s turning every gnat fart in the Clinton White House into a six-part inquiry, and at the end of it, Bill left office historically popular. They’ve spent the better part of the 2010s doing the same thing to Hillary, and though she is emphatically not historically popular, Republicans have, in the process, tended to humiliate themselves and abet Donald Trump—the one person politically incorrect enough to call her crooked and accuse her of playing the woman card, at last, at last.

What we witnessed Thursday was part of a pattern that goes back more than 20 years. A Clinton does something—in some cases innocuous, in this case worthy of criticism—and her political nemeses respond completely out of proportion. They’ve invested so heavily in the fantasy that Hillary’s one email or utterance away from complete self-destruction that they can’t bring themselves to accept anything less than the highest return. A sunk cost fallacy of power politics and partisan score-settling.

The pattern has become familiar enough that reporters now anticipate it. When FBI Director James Comey excoriated Clinton for her sloppy email protocol, it was almost a foregone conclusion that Republicans would peer so deeply into the mouth of the gift horse he’d just given them that they’d pop out the other end. On Thursday, they hauled him up to Capitol Hill knowing that any number of right-wing members on the House Oversight Committee might attack his integrity, and sure enough they did. Now the chase continues.

We will be dealing with the fallout of the email investigation well into Clinton’s first term in the White House.

What made this episode unique is that the same media that expected Republicans to overreach played a critical role in increasing their expectations of a political windfall.