Obama Leads in NBC WSJ Poll

msnbc: In the head-to-head matchup, Obama leads McCain among African Americans (83-7 percent), Hispanics (62-28), women (52-33), Catholics (47-40), independents (41-36) and even blue-collar workers (47-42). Obama is also ahead among those who said they voted for Clinton in the Democratic primaries (61-19).

Yet among white men — who made up 36 percent of the electorate in the 2004 presidential election — Obama trails McCain by 20 points, 55-35 percent. “That is the reason why this election is close,” Hart notes.

In addition, McCain leads Obama among white suburban women (44-38), group which makes up about 10 percent of all voters that Hart calls “absolutely critical” for both candidates in the fall.

However, Obama has a seven-point advantage (46-39) among all white women. How important is that lead? Newhouse explains that Republican candidates always expect to win white men by a substantial margin, but it is white women that usually decide the race. “If a Republican wins among white women, we usually win that election,” he says, noting that George W. Bush carried that group in 2000 and 2004.