Voting for the new health care law was extremely damaging to Democrats’ re-election prospects in 2010 according an analysis by Seth Masket and Steve Greene. From Enik Rising:

For the paper, we look at the impact of four roll call votes: health reform, the stimulus, cap-and-trade, and the TARP bailout from 2008. We find that a vote for health reform was very costly for Democrats, reducing reelection margins by six to eight percentage points. This cost at least thirteen House Democrats their jobs. We find a smaller, but still statistically significant, effect for supporting TARP. The stimulus has a mixed effect, harming Democrats in more conservative districts but possibly helping them in more liberal ones. We found no overall effect for cap-and-trade.

That is a huge impact. So, without this really bad health care bill, Republicans would control the House by roughly a 229-206 margin. A rather minor deficit that would make Democrats chances of taking back the House in 2012 a far more likely prospect.

If only there had been a high-profile website on the left that tried diligently to warn Democrats what a politically toxic event their corporatist sellouts had made a vote for health care reform. A website that even went so far as to pay for polling on the bill in swing districts to prove what a political millstone it had become, and tease out some progressive changes that might salvage it. Although, I guess, such a useful warning wouldn’t have much value if it were subject to several disingenuous attacks by supporters of the law.

Despite fairly clear evidence to the contrary, you had Bill Clinton, Rahm Emanuel, and several liberal writers working to convince Congressional Democrats that, after voting for high-profile and highly unpopular legislation, it would magically become popular soon after passage.

In the future, the health care debate will become a fascinating case study in groupthink. An interesting look at how Republicans were able to get their base so incredibly angry at what was fundamentally a revised version of an old Republican health care plan, and how almost the entire professional Democratic political class was able to delude itself about the politics of the bill.