Did Joe Lieberman contribute to the Democratic debacle?

Did Joe Lieberman’s “incoherent intransigence” on a piece of the health care reform bill contribute to Democrats’ losses Nov. 2? Ezra Klein suggests Lieberman’s dogged opposition to allowing uninsured adults over 55 to buy into Medicare may have hurt the party’s performance. That provision, which died after Lieberman threatened a filibuster, would have taken effect immediately and would have been popular among some key blocs of voters who might have come out to support Democratic candidates, he theorizes.