Jeff already wrote an interesting blog about Specter switching parties.  Specter seems to have switched because he stands a better chance winning in re-election as a Democrat than a Republican, Jeff’s point 4.  The Democrats seem ecstatic and I’m trying to deduce why this is the case.

If Specter had not been accepted into the Democratic fold, he would have lost in the Republican primary.  The Republican candidate, presumably someone very right wing, would then face a Democratic challenger.  This Democrat would be someone other than Specter as Specter would have tried to run as a Republican.  Maybe Specter would run as an Independent in this scenario – though I’m not sure if Pennsylvania allows this.  If the Democrats think that having Specter run as a Democrat means a higher probability of a Democratic win than this messy scenario, I can see some rationale for their happiness.

Their payoff is affected by the quality of Specter as a Democrat as well as his probability of winning.   Specter was pretty independent as a Republican and, for example, voted for the stimulus bill.   So, he is a net gain to the Democrats if he is more likely to vote Democrat than Republican with a “D” label attached to him rather than a “R”.  But he has just shown his lack of loyalty to party by switching sides and was always independent anyway.  His move is very much a rational move made by a calculating politician.  Hence, I believe he is only of use till he is re-elected (or not) in 2010.  Obama has promised to campaign with him and help him raise money.  This is useful till 2010.  After that, Specter will go his own way.    Obama has to get as much Specter-friendly legislation as possible passed in the next two years.  I’m not sure where Specter stands on healthcare reform.  He had cancer and is emotional about health issues.  Maybe this is a point of common value.