Obama leads 50 to 47 percent, which is down from the same poll in June, when Obama led by 6 percentage points, and May, when Obama led by 8.

Romney is buoyed in the poll by independents, who prefer him 51 to 41 percent over Obama. Romney also has a massive lead over Obama among white voters, 57 to 40 percent.

The president continues to dominate among Hispanics, 67 to 28 percent.

Romney has been dogged by a low approval rating throughout the election cycle, and while his favorability rating is still underwater, at 46 percent positive and 49 percent negative, it has improved from 41 percent positive and 53 percent negative in June.

Nevada is one of 12 battleground states — the others are Michigan, Florida, North Carolina, Virginia, Colorado, Wisconsin, New Mexico, Iowa, Ohio, Pennsylvania and New Hampshire — that will be critical in determining the outcome of the 2012 election.