Arlen Specter is a Democrat

I'm surprised this didn't happen earlier. Republicans have been threatening to punish caucus members who break Party discipline for years. Everyone is pointing out that once Franken gets seated the Democrats will have a supermajority. It's really only a theoretical supermajority; you never know when Lieberman or one of the bluedogs will go the other way. Still, even a theoretical supermajority might be enough to make the Senate Republicans start negotiating in good faith. Nothing could make the the House Republicans do that, but the Senate Republicans are less insane (except Jim Inhofe). In the short run, I predict exploding heads on Fox News and a redoubled effort to keep Franken from taking his seat.