One of Molly Ball's three reasons:
The 2010 uprising of the Tea Party issued a stern brushback to GOP elites who sought to influence the process: Anything they said only made it worse. From badmouthing Christine O'Donnell to doubting Sharron Angle, each pronouncement of the Washington establishment was greeted with jeers and pitchforks. This time around, Sarah Palin has explicitly framed her vote for Newt Gingrich as a matter not of actual support for Gingrich, but of defying the establishment's prerogatives and expectations. In the face of this sort of blowback, the voices of the institutional GOP would just as soon sit on their hands and let nature take its course. But it's hard to imagine them waiting all the way through August.
The Dish 