Good question! One of the odder aspects of American politics - at least for foreigners used to the rough and tumble of the House of Commons - is the elevation of bispartisanship to the status of some kind of political sacrament. A cynic would say that the principle motivation for this is to ensure that blame is shared between the parties, not hogged by whomever happens to be in the majority at any given moment. I always have the feeling, mind you, that respectable opinion in DC finds partisanship both excessive and, worse, rather vulgar.
(To be more precise: polite society finds Democratic partisanship especially vulgar; since 1994 and the departure of all those nice, north-eastern Republicans, it has reconciled itself to the fact that, alas, the GOP are a bunch of rednecks and yahoos with no sense of or feel for the way things ought to be done in the capital. They are beyond hope. But Democrats - "people like us" - should know better.)
Anyway and nonetheless, I suspect President Obama would have liked Republican votes for his near-trillion dollar "stiumulus" package. It's safer that way and, in the way that these things are seen in Washington, "better" for the country to "come together" in these difficult times. And perhaps there's something in that. So, it was a surprise to see the GOP reject his entreaties so completely. Not a single Republican in the House of Representatives voted for the bill. Indeed since a handful of Democrats deserted the party line there was greater bipartisan opposition to the bill than there was fo it.
For a party that's been hammered in the last two Congressional elections, this was bold, even admirable stuff. Sure, one can smile at the irny of the GOP rediscovering its opposition to grotesque misuses of public money after eight years in which they willingly, nay slavishly, nodded through every budget-busting, deficit-boosting monstrosity George W Bush asked them to endorse. But there's no joy in heaven like that of seeing a sinner repent, right?
But it's still a big gamble. The Republican party is betting that Martin Feldstein is right. That is, not only is this a bad bill (almost certainly true) but that it's a bad bill that won't even work. True, this is not always a vital consideration in Washington but on this occasion at least the GOP has decided to ask "will it work?" This is an unusual event in itself. If only Democrats had shown similar determination during the passing of the PATRIOT Act. (Of course, in many repsects this "stiumulus" is a kin of economic equivalent to the PATRIOT Act - larded with pet projects and special plans that, though advancing one Congressman's cause, are largely if not completely irrelevant to the stated purpose of the wider, actual bill.)
As Dave Weigel points out, the GOP finds itself in a ticklish political hole. What - gulp! - if it does work? Or what if, unconnected to the stimulus, the US economy recovers more quickly than many expect but voters, prodded by a popular President, give him the credit for the recovery? Disaster! Then again, any economic recovery is probably bad news for Republican hopes in the 2010 midterm elections which, as Mike Crowley rightly says, are already (!) underway. That leaves the GOP in a ticklish political position: it can't be seen to be betting against America but, politically speaking, a quick recovery would be extremely problematic. Then again, such are the agonies of opposition everywhere*.
However, there's much talk in Washington about how the failure to attract Republican votes is also a problem for the President. Please! Sure, everyone cites the 1993 Clinton deficit-reduction plan (also known as, er, tax increases) that supposedly ruined him in 94, but that's not an entirely accurate comparison. Apart from anything else, Clinton was elected with only a plurality of the vote. Obama won with 53% - a landslide in contemporary terms - and, whatever you may think of the man or his policies, he has a mandate to do as he pleases. There's no reason, beyond political calculation or a sense that it might actually be in the national interest, for him to seek Republican support for anything.
The danger for the GOP, mind you, is also that the President may ignore them entirely (just as Dubya ignored and marginalised the Democrats). Opposition for opposition's sake is a concept we're quite comfortable with, but it's not something Washington much cares for. And right now, for all the fat in the "stiumulus" passage, there's some merit to the notion that Republicans should keep some of their powder dry until the new President has, as will inevitably happen, lost some of his sparkle.
Incidentally, will Obama's efforts to "reach out" to Republicans persuade some of the, er, wilder elements of the right that he may not be quite the Marxist radical they imagine him to be? Of course not! Only a genuine Marxist radical would feel the need to camouflage his true intentions in this fashion...
UPDATE: Unsurprisingly, Ben Smith and Mike Allen have good analysis.
*Almost: David Cameron has an easier time of it than the GOP. That's because Barack Obama is popular and, erm, Gordon Brown is not. Decidedly not.