Romney has a significant lead among women, though the race is a virtual four-way tie among men. Romney has large leads in the northeast and western states, but in the vote-rich south, he narrowly trails Cain and Perry -- though he is within the margin of error.
Overall, Romney leads Obama among men in the general election by 12 points; Obama leads by 10 among women. Compared to 2008 exit polls, men have swung towards the Republican by 13 points, while women have moved by just three points.
Romney is particularly outpacing Obama among white men. He leads this group by a 29-point margin, 63 percent to 34 percent. Sen. John McCain, R-Ariz., won among white men in 2008 by 16 points, according to exit polls.
Romney also holds a 13-point advantage among independents, suggesting that his position is stronger than the poll indicates. Obama won independents by eight points in 2008, according to exit polls.
The Pew Research Center poll was conducted Sept. 22-Oct. 4, surveying 1,901 registered voters. The margin of error for the full sample is +/- 2.2 percent. For the sample of Republican and Republican-leaning independent voters, there were 876 respondents, for a margin of error of +/- 3.3 percent.