Potomac primaries make it clear that open primaries favor Obama

[Alhena]

If there had still been any argument about whether open primaries favored Obama, the Potomac primaries ended that argument- Obama carried the open Virginia primary by a bigger margin than the closed Maryland primary even though Maryland has significantly more black voters. Exit polls in Virginia showed Obama got 71% of the Republican vote and similar numbers on the independent vote.

The Texas primary is completely open, so that's a good sign for Obama. Wisconsin is open to independents but I believe it's very easy for Republicans to switch on the day of the primary there. Ohio is open to independents- not sure how easy it is for Republicans to vote in it, however- anyone know?

Pennylvania is closed, which is good for Hillary. However, Pennsylvania follows a 6 week dead period in which she'll have to fight a mass defection of superdelegates to Obama if she doesn't win big in Texas and Ohio.