If there's a default, there will be a lot of finger-pointing, but most of the blame should fall on Republican leadership in the House. TPM's Josh Marshall equated the negotiations between the House, Senate, and administration to a game of chicken, except one of the cars has no driver. No one knows if Republicans have the votes to pass Boehner's, Reid's, or anyone's plan.
Everyone assumes that this is because a large number of congressional Republicans cannot be trusted to raise the debt ceiling. They're even on the record saying things to that effect. But Boehner's inability to control his caucus is his fault.
Here's the thing: If you know that your caucus doesn't want to raise the debt ceiling, or doesn't even really understand what default means, then start whipping early. Make it clear from day one that party members will eventually have to vote to raise it. You can do this in private, make a lot of phone calls, but make it clear that default is not an option. And you do this starting back in March. It doesn't really weaken your hand at the bargaining table, because you're still the guy who has to bring this exceptionally dense Republican caucus on board. That's how Pelosi passed health-care reform; it's what a good leader does.
Of the probable reasons this didn’t happen, one stands out: Eric Cantor. In vying for the speaker's box, Cantor is consistently to the right of Boehner, currying favor with the far right of the caucus. This kept Boehner veering right too. When Boehner would try to negotiate, Cantor would undermine him by pulling out of talks, denouncing any deal that brings in revenue, and even toying with not raising the debt ceiling at all. Of course, Cantor also knew it had to be raised, but instead of bringing the caucus together, he spent the last few months indulging their ideas about the debt ceiling because it put Boehner in a weak spot. Meanwhile, Boehner needs Cantor to help get the caucus in line. Yesterday, a week before the U.S. would stop paying all its bills, Cantor told his caucus to stop whining and vote for Boehner's plan. That's not just terrible leadership. When you're dealing with this particular group of Tea Partiers, it's monumentally shortsighted.
The result is an unknown number of Republicans who have no intention of raising the debt ceiling at all, jeopardizing the entire economy. If the two cars crash, it won't be because Republicans are just too crazy. It will be because Republican leadership was too busy playing politics to put anyone in their car.