Rasmussen is first out of the gates with a national poll of the Republican candidates following Iowa. Santorum has risen 17 points to 21% with Romney at 29%. Gingrich is at 16% and Ron Paul is at 12%. Jon Huntsman and Rick Perry are both at 4%. Romney seems incapable of moving out of the twenties in any of the national polls on the Republican nomination. Santorum has a lot of room to grow, and Romney seems to have hit a firm ceiling for his support in regard to the nomination race.