Rush is in the tank for Santorum.
He only appears to tilt towards Santorum sometimes because it's safe for him to do. Santorum is considered to be a conservative by many but has no chance to win the nomination. If Rush is in the tank for anybody at this point it's Newt Gingrich. He's trying not to make it obvious.
There's NO way Rush would choose Romney over Newt (at this point).
Now if some porn video comes out with Newt and Pelosi or Newt saying something on tape such as "I cannot believe everybody including Rush Limbaugh actually buy everything I say. If only they knew I voted for Clinton both elections" or something devastating... Rush likes Newt. I can tell.
How can anybody like Drudge, Ann Coulter or the list of others actually believe that Romney is more conservative than Newt is baffling to me. They are putting party above all. That's all I can say.