Simon Jackman shows that Specter was the 3rd most liberal Republican in the 111th Congress — although his estimated position on the ideological continuum isn’t much different than Snowe’s or Collins’ (or Nelson’s, for that matter). So now what happens?
Yesterday I posted on how much members of Congress change their voting behavior once they switch parties. Nolan McCarty also weighs in, citing this paper (which I neglected to discuss yesterday):
bq. We found that on average party switchers moved 28 percentile ranks on a liberalism scale. Thus, a Democrat at the 40th percentile on liberalism would move to the 68th percentile. In the 110th Congress, Specter was the 55th most liberal member of the Senate. With the addition of new Democratic senators, he is probably the 62nd most liberal. Consequently, if he shifts the average amount, he’ll be the 34th most liberal. Such a move would put him solidly within the Democratic fold near Herb Kohl and Diane Feinstein. He would probably rank more liberal than his fellow Pennsylvania Democrat Bob Casey (even on issues other than abortion).
bq. That’s just the average effect. There are reasons to suspect that Specter might go even further left. After all, he has to make party activists forget that he voted for the Iraq War, supported Bush’s judicial nominees, and was Anita Hill chief inquisitor (memories are long for these sorts of things). He has to avoid a serious Democratic primary challenge, and he has to raise a lot of money from groups and individuals who have pumped millions into past attempts to defeat him. So Obama just doesn’t get an extra vote for his agenda, he gets an easy vote.
That’s a bold prediction! But I wouldn’t be surprised.
I’m hearing a lot of scuttlebutt about how Specter must have extracted a promise (from Obama, Biden, Rendell) not to support a primary challenger, but my guess is he didn’t extract a promise from Joe Sestak et al. not to challenge him. People get a little excited speculating about these backroom deals, but Nolan is right: those don’t obviate the need for Specter to shore up his left flank, as it were. He’s probably got about 6 months to do that, if he wants to deter a challenger.