Kevin McCarthy might not look stupid.

In the privacy of his home, far away from the TV cameras and the Maga bozos in his Republican caucus, he might not always sound stupid.

But the new House speaker has fully embraced the politics of stupid.

Stupid is picking a political fight you know you are going to lose. Stupid is taking the economy and the markets to the brink of debt default before caving like it’s no big deal. Stupid is pretending to look tough about deficit spending after waving through every budget-busting dollar that Donald Trump wanted to spend.

Stupid is what Kevin McCarthy does. Because Kevin McCarthy was stupid enough to want the job of leading this motley crew of House Republicans in the post-Trump era.

Still, our Kevin is something of a conundrum. He is smart enough to know he’s acting dumb.

After all, he was present and on the job when the House Republicans first tried to prove their macho bona fides. Back in the heady days of 2011, when the Republican party was drunk with the Tea Party, McCarthy was the House majority whip – the third in command – as they thought the unthinkable about defaulting on Treasury debt.

After months of pointless crisis, the Republicans caved and ended up with a package of budget cuts that were vastly outweighed by the billions of dollars in extra costs incurred by the crisis itself. According to the Government Accountability Office, the debt ceiling fiasco cost Treasury an extra $1.3bn in just one year, and billions more in higher borrowing costs for years to come.

But saving money was never the point of this particularly predictable game of chicken. A chicken’s brain is the size of two peanuts, which is at least one peanut bigger than the political brains behind the debt ceiling crisis.

Naturally, the House Republicans fared badly in the polls after 2011, and their attempt to wound then President Obama succeeded so well that he sailed to re-election the following year.

Having learned precisely no lessons from their failures, they repeated the same chicken run in 2013, when they caved again with even less to show for the self-inflicted crisis than they salvaged two years earlier.

Kev was still majority whip for that second Hail Mary, but why stop when you’re losing?

This is the Republican leader who just lost 14 votes to grab the job of speaker, and succeeded only at the 15th attempt by offering what was left of his peanut-sized dignity as a ritual sacrifice to the craziest collection of Trump-inspired loons outside Florida.

There’s a reason why Marjorie Taylor Greene has been handed a seat on the House homeland security committee. It’s either because of her desire to investigate the gazpacho police or the Jewish space lasers. Only time, and some delicious cold soup, will tell.

In his private moments, Kevin can probably make sense of this insanity by telling himself that goddamit he’s all that stands between us and the end of civilization. Who else could possibly bridge the divide between the Trumpy-trons and regular, white middle America?

If it weren’t for our Captain Kevin, they would still be voting for a House speaker and Marjorie Taylor Greene would have seized control of all the lasers.

So what if he had to humiliate himself to get the job? It wasn’t the first time. He had to humiliate himself by groveling to Trump after that nasty insurrection thing got out of hand on January 6. Sometimes you have to take one for Team America.

But these delusions can only take you so far: to the end of the cliff, where the lemmings finally realize the folly of their decisions.

At the very point where the debt ceiling crisis ends, the speaker’s real suffering starts to kick in.

Because that’s when the Kev-meister stares down the reality of the deal he made with the devil to get his job in the first place. This is the so-called motion to vacate, giving one single, unhinged House Republican the ability to call for a vote to fire their so-called leader.

You see, the debt ceiling crisis is not, in fact, a show of strength by the House Republicans and the political mastermind who sits in the speaker’s office. It is a demonstration of weakness, unfolding over many months, with only one destination: the debt ceiling lifted, and the end of Kevin McCarthy’s career.

For now, McCarthy is the only one at the negotiating table over the debt ceiling. Even his Republican partner in the Senate, Mitch McConnell, will have nothing to do with this nonsense.

“I would like to sit down with all the leaders and especially the president and start having discussions,” said the incredible shrinking speaker. “Who wants to put the nation through some type of threat at the last minute with the debt ceiling? Nobody wants to do that.”

Nobody, except Kevin. Nobody knows the trouble Kevin has seen. And nobody but Kevin knows how lonely he feels.

It was his old boss, John Boehner – the House speaker who tried and failed to stare down President Obama over the debt ceiling – who put it best: a leader without followers is just a man taking a walk.

Kevin McCarthy is just a small man, talking a big game, taking a long walk off a short pier.

• Richard Wolffe is a Guardian US columnist. He is the author of Renegade: The Making of a President