“You’ve got to know when to hold them and when to fold them”—thus spake Michele Bachmann in an interview with The Washington Post last week. Bachmann is, of course, the high priestess of not knowing when to fold them. In 2012, she alleged an Islamist conspiracy at the top levels of the U.S. government. Even after the allegations swept her into a polar vortex of criticism--“[t]hese attacks have no logic, no basis, and no merit and they need to stop,” protested John McCain—Bachmann refused to back off. And yet, on the subject of a possible debt-limit showdown with the White House, an event that once loomed with Megiddo-like significance in Tea Party eschatology, Bachmann told the Post that “[t]here is a pragmatism here … most of us don’t think it’s the time to fight.”

Assuming Bachmann is right about the mood of her fellow conservatives, and the Post story suggests she is, one feels moved to ask: What the hell happened? It’s not just the debt ceiling fight, after all. In the past several weeks, the once-proudly nihilistic Republican House has managed to approve a bipartisan farm bill—a piece of legislation Tea Partiers torpedoed just six months earlier—as well as a budget deal that Paul Ryan hammered out with his Democratic Senate counterpart. And the mellowing appears to extend to Tea Partiers outside the House too. The president of Heritage Action, the lead instigator of GOP brinkmanship over the past few years, now talks charmingly of the need for an affirmative “reform agenda” so that the group can shed its obstructionist image.

In trying to explain this new circumspection, commentators have naturally seized on the fiasco that was last fall’s shutdown, which is useful as far as it goes. But, at the time, it was hardly obvious that the shutdown would have a chastening effect. The real question is why it had such an effect. Only that can tell us how Democrats should respond.

Before we get to that, however, it’s worth reviewing what the shutdown did not accomplish. It emphatically did not cure Tea Partiers of their darkest fantasies. They still yearn for a violent confrontation with the president, or at least any chance to humble him. That explains why so many right-wingers are demanding something—anything—in exchange for raising the debt limit, even if they realize they have no leverage to extract a meaningful concession. At its most farcical, the Republicans’ debt-ceiling strategery has devolved into a search for demands that are likely to be satisfied anyway—like the so-called Medicare doc fix—so they can claim they forced Obama to give ground. (My own suggestion: Refuse to raise the debt ceiling unless Obama promises to join Michelle and the kids for dinner every night that he’s in town—an honest-to-goodness pro-family ritual, albeit one he’s been practicing for over five years.)

In fact, the shutdown didn’t change much of anything about the Tea Partiers themselves. It just gave us some insight into what governs their behavior. To borrow the reigning metaphor of this discussion, it’s not that the shutdown broke the fever. It’s just that we now can now say whether the illness is viral or bacterial.