CNN/ORC International survey said in hypothetical match-ups, if the election were held now, Obama would beat former Massachusetts Gov. Mitt Romney 54 percent to 43 percent and former U.S. Sen. Rick Santorum of Pennsylvania 55-42. Both margins are wider earlier polls had shown, CNN said.
The poll indicates Obama's approval rating nudged above the 50 percent mark for the first time since May.
While most Americans still view the U.S. economy as struggling, there was a 13 percentage-point increase since January in the number who say it's in good shape.
"President Obama currently wins majority support among groups that have been problematic for him in the past, including men, older voters, and suburbanites," CNN Polling Director Keating Holland said. "He has a solid lead among independents as well."
The telephone poll of 1,014 adults nationwide, conducted by ORC International Saturday and Sunday, has a margin of error 3 percentage points.