WaPo's Michael Shear wrote in an online discussion today:

Because the Republicans largely abandoned the stimulus bill, the Democrats are the ones that will own it -- for good or ill. If it succeeds in producing jobs and getting consumer spending going again, I suspect there will be Republicans who regret their opposition. On the other hand, if the consensus in six or eight months is that it has failed, or was the wrong mix, then the Democrats will have to accept the consequences of their decision to push for it.

This is pretty much conventional wisdom. But there's a problem with it: it assumes that if the stimulus doesn't work, the Republicans will have been right -- that there should have been more tax cuts and less spending.

But many economists think that if anything, the stimulus package did not contain enough spending. Given that the Republicans were loudly arguing against spending -- even going so far, with help from the media, as claiming that spending and stimulus were contradictory concepts -- it seems clear that if the bill doesn't work because it didn't spend enough, Republicans will deserve the “consequences” of their opposition.

Whether they “will have to accept” those consequences will depend largely on how the media covers it all. If they assume -- as Shear seems to -- that failure will mean the stimulus should have included less spending, Democrats likely have the blame all to themselves. But if economists believe the problem with the stimulus was that there should have been more spending -- and if the media makes that clear -- Republicans will sure in the blame.

Put another way: Democrats may “own” the stimulus, but Republicans share ownership of the fact that it wasn't bigger. If the stimulus doesn't work, and insufficient spending turns out to be the reason, Republicans will own a large share of the blame.