Progressives in of favor congestion pricing on highways and in central cities tend to argue for those policies on progressive grounds (shock!) -- that such pricing systems reduce emissions, improve air quality, and fund transit improvements, which benefit lower and middle income households. Those are all nice benefits to congestion pricing programs, but we shouldn't neglect the congestion reduction function.
Congestion costs America some $80 billion per year, in the form of lost time and wasted fuel. And as it turns out, commutes extended by congestion have other effects, as well:
Back when everyone was discussing whether or not we should bail out the automakers, some folks were suggesting that saving the Big Three could help Detroit transition into a hub for the production of green technologies. I tended to point out that the Big Three had often fought against policies that would encourage green innovation, so saving the automakers would maintain a major institutional barrier to a Midwestern economic renaissance.
The conservative economists who have argued against the stimulus, as a whole or in parts, have generally tried to do so in a reasonable fashion. I mostly think they've got it wrong, but they're at least trying to use theory and data to assemble a coherent story about why the stimulus might be a bad idea.
The conservative punditocracy has not held itself to such high standards. As the stimulus bill gets closer to becoming stimulus law, their arguments seem to be getting worse. They're simply freaking out at the idea of the thing.
The passage of an economic recovery package was never going to be a particularly clean or easy process. We have a brand new president and Congress, with a Republican minority prepared to sacrifice good policy for partisan victory. We have the worst economic crisis in decades, which appears to be gathering momentum at a frightening pace. And so we have the pressure to act boldly and very swiftly -- pressure that might have been reduced by the passage of a smaller, stop-gap stimulus bill last session, but of course legislators were preoccupied with the automakers at the time.