A new Rasmussen survey shows Rick Santorum has jumped to a 12-point lead over Mitt Romney nationally in the race for the GOP presidential nomination.
Santorum leads with with 39%, followed by Mitt Romney at 27%, Newt Gingrich at 15% and Ron Paul at 10%.
Key finding: "Perhaps more tellingly, Santorum now trounces Romney 55% to 34% in a one-on-one matchup among likely GOP primary voters. This is the first time any challenger has led Romney nationally in a head-to-head match-up."