If Paul Krugman's at the point where he's throwing up his hands and saying the Republicans are plain batshit crazy, we're probably somewhere near the end of the political line:

Right now, if inherent importance were all that mattered, I wouldn’t be writing about the effects of sprawl, or the Fed succession, or even, probably, about China’s brick-wall problem. I would instead be writing all the time about the looming chaos in U.S. governance.

In the short run the point is that Republican leaders are about to reap the whirlwind, because they haven’t had the courage to tell the base that Obamacare is here to stay, that the sequester is in fact intolerable, and that in general they have at least for now lost the war over the shape of American society. As a result, we’re looking at many drama-filled months, with a high probability of government shutdowns and even debt defaults.

Over the longer run the point is that one of America’s two major political parties has basically gone off the deep end; policy content aside, a sane party doesn’t hold dozens of votes declaring its intention to repeal a law that everyone knows will stay on the books regardless. And since that party continues to hold substantial blocking power, we are looking at a country that’s increasingly ungovernable.

The trouble is that it’s hard to give this issue anything like the amount of coverage it deserves on substantive grounds without repeating oneself. So I do try to mix it up. But neither you nor I should forget that the madness of the GOP is the central issue of our time.