If John Boehner is to be believed — which, admittedly, is a real question — Republicans are once again willing to push America into default and/or shut down the government if they don’t get their way. As Greg Sargent points out, this is amazing — and what’s equally amazing is how this is being treated as normal. Politics ain’t beanbag; but “I’ve got a bomb strapped to my chest, and the whole room gets it if you don’t hand over the money” is not normal tactics, especially if pursued repeatedly.

What adds to the awesomeness of the whole phenomenon is the absence of any halfway plausible rationale. To the extent that there ever was an economic justification for this brinksmanship — the claim that we were on the verge of a debt crisis, the claim that slashing spending would boost the economy — that justification has collapsed in the face of declining debt projections and overwhelming evidence that austerity has large negative impacts in a slump. True, as David Firestone notes, leading Republicans seem to have a hearing problem; they are so deep into their worldview that when, say, Ben Bernanke refutes that view they simply hear him saying the opposite of what he actually said.

Still, how can the GOP be acting this crazy again? This time around, it’s hard to see Obama caving in. So why the brinksmanship?

Well, my guess is that despite being drenched in reality-repellent, Republicans are beginning to suspect an inconvenient truth: Obamacare is not going to be a self-destroying train wreck. Instead, it’s going to work — not perfectly, not as well as it should, but well enough to help far more people than it hurts. And if that’s how it turns out, it will be irreversible. So here comes a last-ditch effort to stop it, at all costs.

But think about that for a moment: the cause for which the GOP is willing to go to the brink, breaking all political norms, threatening the US and world economies with incalculable damage, is the cause of preventing people with preexisting conditions and/or low incomes from getting health insurance. Apparently, the prospect that their fellow citizens might receive this help is so horrifying that nothing else matters.