Now it gets really interesting. Republicans in the House are determined to shut down the government, by holding defunding of Obamacare hostage for continued funding of the rest of the budget. In past budget negotiations, Obama has often been too quick to fold a strong hand. But this time, the Tea Party badly miscalculated. They targeted Obama's personal crown jewel, the one piece of progressive social legislation that the president won't throw under the bus. So a showdown is increasingly likely, and Democrats could well win it. The shutdown scenario could backfire on the right in several respects. First, Republicans are split at least three ways on how to play this game. The Tea Party is spoiling for this showdown, but the House and Senate GOP leadership wants to avert it. Even Karl Rove has argued against it.