It sure seems, as Karen Tumulty tweeted earlier today, that House Republicans have been BTU’d by their leadership: They’re going to be saddled with an ugly Medicare vote without even getting close to having any results to show for it (see also Ezra Klein’s explanation, and more from Steve Benen). Since it’s hardly a surprise that slashing Medicare turned out to be unpopular and that Democrats in the Senate and the White House were going to reject the GOP plan, the question is, why? Why did John Boehner put Paul Ryan’s plan on the House floor to begin with? It sure seemed to me that the obvious path was to skip the unnecessary step of passing a budget. So why did they go ahead? I can think of three possible reasons:

1. It’s the Bob Bennett House. Members of Congress are normally incredibly skittish about anything that might hurt them in the next election. But after Bob Bennett was denied renomination last year – and after Lisa Murkowski, and several other primary surprises – Republican members are so paranoid about primary challenges that they’ve decided to ignore general-election threats. By the way, that wouldn’t be totally nuts of them; it’s very possible that a Medicare vote might hurt a few points in November 2012, but that won’t make the difference in many districts, while doing something that alienates movement conservatives and sparks a primary challenge is probably a real, if exaggerated, danger.

2. Epistemic closure. Republicans are so trapped in the conservative misinformation feedback loop that they honestly didn’t realize that Ryan’s VoucherCare was likely to be highly unpopular. This could be true either of the leadership or the rank-and-file members, or both.

3. Incompetence. Never count this one out. It’s possible that Boehner just mismanaged the whole thing somehow. Either he promised Ryan a vote before realizing what would be in the budget, or he didn’t realize what they were voting on, or some other possibility.

I’ve been impressed by Boehner up to this point, so I’m leaning toward some combination of explanations (1) and (2). What do you think?