In a hypothetical match-up, Forty-nine percent of registered voters said they would vote for Obama for president, while 45 percent said they would choose Romney, the front-runner in the GOP nominating race, results from a Gallup poll released Monday indicated.
While Obama's advantage is within the margin of error, Gallup said it was the largest lead he has held over Romney in Gallup polling to date.
Obama had 51 percent-to-43 percent lead over Rick Santorum, Romney's main rival for the Republican nod, the Princeton, N.J., polling agency said.
Results also indicated Obama held a 51 percent-to-42 percent edge over Romney in a Gallup-USA Today poll in 12 key swing states. The president polled ahead of Santorum in the swing states, 52 percent to 41 percent.
Results for the match-up poll are based on nationwide telephone interviews of 901 registered voters conducted March 25-26. The margin of error is 4 percentage points.
Results for voters in 2012 election swing states are based on telephone interviews conducted March 20-26 on the Gallup Daily tracking survey with 933 registered voters living in Colorado, Florida, Iowa, Michigan, Nevada, New Hampshire, New Mexico, North Carolina, Ohio, Pennsylvania, Virginia and Wisconsin. The margin of error is 4 percentage points.