Forty-eight percent said they back Obama and 46 percent said they support Romney, results of a USA Today-Gallup Swing States poll released Wednesday indicated.
The results are based on a poll of registered voters in Colorado, Florida, Iowa, Michigan, Nevada, New Hampshire, New Mexico, North Carolina, Ohio, Pennsylvania, Virginia, and Wisconsin.
Results indicated 22 percent of voters were either undecided or said they could possibly change their minds about whom to support between now and Election Day.
The candidates have roughly the same percentage of committed voters, the Princeton, N.J., polling agency said. Thirty-nine percent of Romney supporters and 38 percent of Obama backers in the swing states say they wouldn't change their preference.
Most swing-state registered voters, 74 percent, said the recent political conventions had little to no influence on them, Gallup said. Three in four said they didn't think the presidential debates would influence their vote.
Results are based on telephone interviews conducted Sept. 11-17 with 1,096 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.