So, now the odds are that we're headed towards a government shutdown. For those of you who'll want to say it's Obama's fault because he refused to accept this new extension offer from the GOP, I note that that came with a massive string attached: cuts of $12bn more to the domestic discretionary budget. That is not parcelled out over the fiscal year. That's $12bn in that one week. And that's on top of the $10bn already cut in the two previous continuing resolutions. Finally, Obama said "enough".

No, it's definitely the GOP that's driving the shutdown. Why? On the surface, the "why" is over the size of cuts. But I mean: really, really, really why. I have two theories:

1. It's a kind of psychological thing among especially (but not limited to) the new members: they came here to shake things up, not go along and get along; and this is shaking things up. We all have these moments in our lives where we actually want to precipitate a crisis, just to see what would happen and to show observers that we mean business.

Fascinating little report in Politico today, in which a source from inside that fateful GOP House caucus meeting Monday night spilled some beans:

"The Democrats think they benefit from a government shutdown. I agree," Boehner said during a closed-door, 90-minute meeting on House Republicans on Monday night, according to several lawmakers who attended the session. Boehner's opinion was quickly backed up GOP lawmakers who were serving in Congress during 1995, when former speaker Newt Gingrich (Georgia) squared off with then-President Bill Clinton by shutting down the government twice. Reps Don Young (Alaska), Dana Rohrabacher (California) and Buck McKeon (California) – a close ally – supported Boehner's position. Dozens of other Republicans rallied to support Boehner as well, in a moment that one GOP insider called a "turning point" for House Republicans. "My view is that a government shutdown doesn't benefit anyone necessarily, but if one party or the other is going to get an edge, it's probably the Democrats. I agree with the speaker there," Rep Steve LaTourette (Ohio) told Politico. "If you look at the government shutdown of 1995, it guaranteed President Clinton's re-election. And that's what this would do. If you want to cede the presidential race in 2012, you shut down the government." But while Boehner may have backing from the old veterans in his camp, he's run headlong into the Tea Party group of House Republicans who believe that Obama and Senate Democrats would come off the worse if a shutdown actually takes place. These hardline Republicans, not all of whom are freshmen, have forced Boehner to play hardball with the Democrats or face a potential threat to his own survival as speaker. This hardcore faction is insisting on no less than the $61bn spending cut package passed by the House in February, and they've refused to back to any proposal that includes smaller reductions […] The split among Republicans breaks somewhat along generational lines, but even more clearly between those who have served in government – either in the state, local or federal level – and those who have never done so.

So they're being told by people with experience that they're going to hurt their party, and they don't care. And how about that LaTourette fellow, eh? LaTourette's Syndrome: saying things publicly that many people think but wouldn't even say privately.

So that's theory one: they came here to fight and they just want to get it on. Once that psychology gets in a certain number of brains, a tipping point is reached.

2. It's about economics and the presidential election. The GOP knows that if the economy keeps improving and unemployment is down to 8% by election time, their chances in 2012 are fairly slim. Now, I hasten to note that that is a big if, so who knows? But everyone understands this.

A shutdown affects the economy immediately and directly. Hundreds of thousands of people in the public sector aren't working and therefore aren't spending. Hundreds of thousands more in the private sector who depend almost entirely, or at least largely, on government contracts for their livelihoods are out of luck. This is everyone from GM to pencil manufacturers. A huge swath of the economy just closes. If the shutdown lasts long enough, layoffs come along. Two bad months slow the tender momentum that now exists.

There you are. Psych and Econ.