Ever since Pennsylvania's Democratic presidential primary, there's been a lot of talk about Barack Obama's problem with white blue-collar voters. In Indiana and North Carolina, whites without a college degree voted for Hillary Rodham Clinton by about 2-to-1, according to the network exit poll: 65 percent to 34 percent in Indiana; 68 percent to 26 percent in North Carolina. In the Democratic primaries through May 7, white noncollege voters have gone for Clinton in 28 states. They've gone for Obama in only three: Utah, Vermont, and Wisconsin.

Obama is well aware of the problem. "We keep on thinking we have dispelled this, but it keeps getting raised again," the senator from Illinois said in Chicago in March. "People have said, 'Well, maybe he can't win the white blue-collar vote.' ... In each state, we have to prove this stuff all over again."

He doesn't sound as if he sees it as a long-term problem. "This whole notion that somehow, because there are some voters, whether it's older voters or blue-collar workers, who prefer Senator Clinton over me, that somehow that means I can't get their vote [in November]--that just isn't borne out by history," Obama said last month in Pennsylvania. "The party's going to come together after the nomination's set."

That's one way of looking at it. The other is that demography is destiny. The red-blue division in American politics--a division that Obama has set out to heal--seems to have infected the Democratic Party. Clinton wins "red" Democrats (older, less affluent, less-educated whites and Hispanics). Obama wins "blue" Democrats (African-Americans and younger, wealthier, well-educated whites). After all, the candidates had seven weeks to campaign in Pennsylvania. Yet, in the end, nothing much changed: Pennsylvania voted just like Ohio.

What is Obama's problem with white working-class voters? Is it race, or is it class? According to Stuart Rothenberg, editor of The Rothenberg Political Report, "Some of it is race, some of it is his life experience and his style, and arguably some of it is his ideology."

His style? Rothenberg explained, "He talks at 35,000 feet. He's much more of a professor giving a lecture than he is a candidate trying to connect with real people." Obama is trying, though. He went bowling. He played basketball. He says the right things. "We have been missing a president who doesn't choke saying the word 'union,' " Obama told the United Food and Commercial Workers in Chicago. In Indiana, he noted correctly (if a bit professorially), "At the same time that the economy has expanded over the last seven years, average family income has gone down a thousand dollars. This is the first economic expansion in [U.S.] history when that has happened."

Why do white working-class voters prefer Clinton? In Rothenberg's view, "Hillary's got this tough, fighter image, and she does pepper her comments more in terms of the little people--more specifics, more about issues." For example, in Indiana she said, "I have a specific set of plans, an economic blueprint I have laid forth to let people know what I would do--not just talking and promising jobs."

How much of Obama's problem is race? In Pennsylvania, white noncollege Democrats who said that race was an important factor in their vote went for Clinton over Obama by 4-to-1 (79 percent to 20 percent). But 80 percent of white working-class Democrats said that race was not important. They voted for Clinton, too, by better than 2-to-1 (68 percent to 32 percent). That suggests that Obama's problem is only partly racial. A lot of it is cultural.

And the debate over a gasoline tax suspension well captures his challenge. Clinton defends the proposal as a sign of her commitment to help people. "People are hurting," she says in an ad. "It's time for a president who's ready to take action now." An Obama ad accuses her of "political pandering." He said in Indianapolis on Saturday, "There is not an expert out there who believes that this is going to work. There is not an editorial out there that has said this is actually the answer to high gas prices."

This article appeared in the Saturday, May 10, 2008 edition of National Journal.

Want to stay ahead of the curve? Sign up for National Journal’s AM & PM Must Reads. News and analysis to ensure you don’t miss a thing.