Romney, meanwhile, has climbed to a 50 percent favorability rating, with 44 percent saying they do not care for the likely Republican nominee. Support is more solidified for Obama — voters are more likely to have "very" favorable or unfavorable opinions — while their allegiances, one way or the other, are less passionate for Romney.

“The number of voters who say they have a ‘very unfavorable’ view of President Obama has gone up six percentage points to 43 percent just since May,” said Civitas President Francis X. De Luca in a statement. “Meanwhile, though Romney has been hit with a barrage of attack ads, in those two months his favorable rating crept up two points to 50 percent. Now he’s also closing in on a majority when voters indicate who they’d vote for.”

The poll also found a remarkably low number of undecided voters. The 3 percent who said they did not yet know who they would vote for is the lowest of the cycle; as recently as May, twice as many respondents said they had not made up their minds.

“Obviously it’s still close and much could happen,” De Luca said. “But as voter sentiment solidifies, it will become more difficult for President Obama to pull support away from Romney, especially if, as reported, Romney has a financial advantage over the Obama campaign for the final phase of the presidential race.”

North Carolina's 15 electoral votes were a surprise pick-up for Obama in 2008, and Democrats are looking to solidify that gain this year by bringing their national convention to Charlotte. But the state's relatively conservative social politics could make it a tough pick-up in the fall, especially after the president came out in favor of gay marriage earlier this year.