A new poll shows President Obama maintaining a narrow lead over Mitt Romney in pivotal battleground states, posting a 2-point advantage in the 12 contests expected to decide November's presidential election.

The president's 47 to 45 percent lead in the survey, released Sunday evening by USA Today and Gallup, mirrors his standing from the same poll conducted in May.

The survey included voters in Colorado, Florida, Iowa, New Hampshire, Ohio, Nevada, Virginia, Michigan, Wisconsin, Pennsylvania, New Mexico and North Carolina.


The selection of states could partly explain the president’s lead in the poll. Great Lakes states like Michigan, Wisconsin and Pennsylvania are expected to favor Obama, as is New Mexico. Romney, meanwhile, is favored in Nevada and North Carolina.

But the president's edge does inflate when the survey is expanded to include all of the United States, with voters favoring Obama over Romney 48 to 44 percent.

The president has likely been buoyed by his campaign's decision to spend aggressively on advertising early in the campaign. Of those in the swing-state survey who say commercials have changed their opinion on whom to vote for, some 76 percent say they now favor Obama, versus 16 percent who say they've switched their vote to Romney.

"It is becoming clear that as voters learn about the negative impact his time in business had on many middle-class families, the more concerned they are about the kind of president he would be," said former White House aide Bill Burton, who is running the super-PAC supporting President Obama, in a statement.

Meanwhile, the Romney campaign issued a memo to reporters Monday morning noting that they had been outspent 3 to 1 on commercials.

"Unfortunately for them, their factually inaccurate attack ads, while plentiful, have been ineffective," said Romney spokeswoman Andrea Saul in a statement, noting polls remained relatively stable over the past few months

The USA Today/Gallup poll was conducted from June 22 to 29 and has a 4-point margin of error.