Never mind the $10,000 bet he once offered to Texas Governor Rick Perry. Mitt Romney’s best bet to win the Republican presidential nomination is Newt Gingrich’s ego. Since Iowa, Gingrich and Rick Santorum have been fighting for the right to take on Romney as the one and only true conservative in the 2012 contest. The trouble is, they are still fighting each other. As of Tuesday, it’s a tougher case than ever for Gingrich to make.