The speaker of the House is the only congressional officer mentioned in the Constitution, other than a temporary Senate officer to preside when the vice president can’t. The speaker’s job isn’t defined, but surely it includes passing legislation that keeps the federal government running.

But Kevin McCarthy, the current speaker, isn’t doing that job. Indeed, at this point it’s hard to see how he can pass any bill maintaining federal funding, let alone one the Senate, controlled by Democrats, will agree to. So we seem to be headed for a federal shutdown at the end of this month, with many important government activities suspended until further notice.

Why? McCarthy is a weak leader, especially compared with Nancy Pelosi, his formidable predecessor. But even a superb leader would probably be unable to transcend the dynamics of a party that has been extremist for a generation but has now gone beyond extremism to nihilism.

And yes, this is a Republican problem. Any talk about dysfunction in “Congress,” or “partisanship,” simply misinforms the public. Crises like the one McCarthy now faces didn’t happen under Pelosi, even though she also had a very narrow majority. I’ll come back to that contrast. First, let me make a different comparison — between the looming shutdown of 2023 and the shutdowns of 1995-96, when Newt Gingrich was speaker.

If you had told me back then that I’d someday hold up Gingrich as a model of rationality, I wouldn’t have believed you. But hear me out.

Back in 1995, while Gingrich’s tactics — his willingness to employ blackmail as a political strategy — were new and dangerous, he had an actual policy goal: He wanted to force major cuts in federal spending.

Furthermore, Gingrich tried to go where the money was. The federal government is an insurance company with an army: The great bulk of nonmilitary spending is on the big safety-net programs, that is, Medicare, Medicaid and Social Security. And Gingrich in fact sought deep cuts in Medicare and Medicaid.

He didn’t get them, and the government’s role in promoting health insurance coverage eventually expanded greatly — although Medicare has been surprisingly successful at containing costs. Still, Gingrich’s goals were at least coherent.

McCarthy, in his desperate efforts to appease his party’s hard-liners, has acted as if their refusal to approve federal funding is a Gingrich-like demand for reduced federal spending. He tried to pass a continuing resolution — a bill that would temporarily keep the money flowing — that involved deep cuts to certain parts of the federal government.

But there are three notable aspects to this attempt. First, even if he had managed to pass that resolution, it would have been dead on arrival in the Senate.

Second, unlike Gingrich back then, McCarthy tried to go where the money isn’t, slashing nonmilitary discretionary spending. That’s a fairly small part of the federal budget. It’s also a spending category that has already been subject to more than a decade of austerity, ever since President Barack Obama made concessions to Republicans during the debt ceiling confrontation of 2011. There just isn’t any significant blood to be gotten out of this stone.

Finally, even this extreme proposal wasn’t extreme enough for Republican hard-liners. I liked what one representative told Politico: “Some of these folks would vote against the Bible because there’s not enough Jesus in it.” The point is that the party’s right wing isn’t actually interested in governing; it’s all about posturing, and the budget fight is a temper tantrum rather than a policy dispute.

If the G.O.P. were anything like a normal party, McCarthy would give up on the right-wingers, gather up the saner Republican representatives — it would be misleading to call them “moderates” — and make a deal with Democrats. But that would almost surely cost him the speakership, and in general more or less the whole G.O.P. is terrified of the hard-liners, so the party’s positions end up being dictated by its most extreme faction.

As I said, all of this is very different from what happens on the other side of the aisle. You still sometimes see analyses that treat Democrats on the left and Republicans on the right as equivalent, but they’re nothing alike. The progressive wing of the Democratic Party is, in fact, interested in policy; it tries to push the party’s leadership in its direction, but it’s willing to take what it can get. That’s why Pelosi, with only a narrow majority during Biden’s first two years, was nonetheless able to get enacted landmark bills on infrastructure, climate and technology, while McCarthy can’t even keep the government running.

Now, a protracted shutdown would be highly disruptive, and if past confrontations are a guide, the public would blame Republicans — which is what led Gingrich to back down in the 1990s. But it’s not clear that McCarthy, or whoever replaces him if he’s overthrown, would be willing or even able to make a deal that reopens the government. How does this end?