Peter Orzsag says small stimulus size was due to political constraints...

Here's his talk.

I disagree. I'm sure when he was in the room and Democratic Congressman who's jobs depend on having had a large stimulus were demanding a stimulus which was clearly too small it might have clearly seemed like there was "no choice". In fact, however, there are a number of things the administration could have done had they really believed the stimulus was too small. One thing the White House should have done is just to say, flat out, that they think the stimulus was too small but that they didn't think Congress would pass more. Another thing they could have done is announce a larger stimulus in the first place -- which needed no negotiations with Congress. Third, they could have done the AMT patch, which would have been done anyway, separate from the stimulus. Fourthly, they could have merely pushed a $600 billion "net stimulus" which excluded the AMT patch and the $400 billion in counteracting measures at the state and local levels.

Also, we've had a bevy of complaints, at the time and since, from Congressman such as Peter DeFazio that "Larry Summers hates infrastructure". I think there must have been people in the administration who themselves didn't want a larger stimulus, or at least, didn't realize it was something worth fighting for...