In Iowa, a Gravis Marketing poll found the president hitting the crucial 50 percent threshold, leading Romney there 50 to 46 percent. As in Florida, there was a noticeable gender gap in Iowa, but this time in the president's favor: Obama led Romney among women by 23 percent, while Romney led with men by 18 percent.

Still, there are encouraging signs for the Republican challenger. Romney leads among independents in the state 48 to 36 percent, and more Iowans say the country is headed in the wrong direction by a 4-percentage-point margin. 

Gravis also polled Nevada, and again, the president was found to be clinging to a narrow advantage in the state. Obama leads Romney 50 to 49 percent there, but Romney is dominating the president among political independents, with some 68 percent favoring the Republican nominee. 

In New Hampshire, a poll by New England College showed Obama leading Romney 49 percent to 46 percent. Romney's advantage was primarily with voters over the age of 65, while the president posted a solid advantage among younger voters.

A OnSight Public Affairs poll of Colorado — which has shaded increasingly toward Romney in recent weeks — also showed some momentum for the president, who led his Republican challenger 46 to 45 percent there. Unlike other states, the president posts a 52 to 38 percent advantage with unaffiliated voters in Colorado, driving him to the lead. The president also held a nearly 4-1 lead with Hispanics and a 52 to 41 percent advantage with women, although that was offset somewhat by Romney's 52 to 42 lead among men.