Rasmussen Shocker: Romney leads President Obama by five points in a hypothetical 2012 matchup

Mitt Romney would beat Obama 48-43 if the election were held today. Santorum is up by only 1 over Obama.

Via Rasmussen:

With the perception growing that he will be the GOP nominee, Romney leads President Obama by five points in a hypothetical 2012 matchup. Today's numbers show Romney at 48%, Obama at 43%. That’s Romney’s largest lead since December. Matchup results are updated daily at 9:30 a.m. Eastern (sign up for free daily e-mail update).

If Santorum is the Republican nominee, he is up by one point over the president, 46% to 45%. This is the second time since polling began in 2011 that Santorum has had a slight lead over Obama. Romney is the only other candidate to lead the president more than one time in the polls. See tracking history   for Obama vs. all four Republican candidates.