Published: Mar 28, 2012 11:16 AM EDT

TALLAHASSEE, Fla. (AP) - A new Quinnipiac University poll shows President Obama opening a lead over Republican hopefuls Mitt Romney and Rick Santorum in three key swing states.
 
Obama leads both Republicans outside the margin of error in Florida and Ohio and has a slight lead over Romney, 45 percent to 42 percent, in Pennsylvania. Obama held a 48-41 advantage over Santorum in Santorum's Pennsylvania home state.
 
The president topped Romney 49 percent to 42 percent and had a 13-point bulge over Santorum in Florida and led Romney 47 percent to 41 percent and Santorum 47-40 in Ohio.
 
Quinnipiac's survey of 1,228 voters in Florida taken between March 20 and March 26 had a margin of error of plus or minus 2.8 percentage points in the three states.