As Sen. Barack Obama closes in on the Democratic nomination, a potentially challenging storyline for his campaign has emerged: He's yet to make his case with the working-class voters.
Exit polls in Tuesday's Kentucky primary were the latest to point to that problem. The numbers suggest that Sen. Hillary Clinton's supporters are fiercely devoted to her.
Nearly half of the state's Democratic voters said they'd either vote for Sen. John McCain, the presumptive Republican nominee, or not vote at all in November if Obama is on the ticket.
Those voters have overwhelmingly backed Clinton in previous contests, but they're not a lost cause for Obama, experts say.
In order for him to win their support in the general election, he needs Clinton in his corner, he needs to convince them that he can help alleviate their economic woes, and he needs to connect with them on a personal level, according to the experts.
But despite those numbers, support for Clinton is not necessarily Obama's loss in a general election, said Mark Peffley, a professor of political science at the University of Kentucky.
"I think what voters say now as a justification ... for being committed to a candidate is not going to be their sentiment during the general election," he said.
Clinton and Obama have mobilized different parts of their party. She appeals to the blue-collar voters, and Obama has been more successful with affluent, well-educated Democrats.
If Clinton throws her support to Obama and the party rallies behind him, Clinton's supporters will probably follow suit, Peffley said.
Right now, Democrats are choosing between Clinton and Obama, who have similar policies. In the general matchup, the differences between the Democratic candidate and McCain will be much more distinct.
"I can't imagine that anyone who would vote for Hillary Clinton would end up voting for McCain. If you look at the issues, there's a huge divide between Hillary and McCain," Peffley said.
Stephen Voss, a specialist in elections and voting behavior and a professor at the University of Kentucky, said that given the disappointment of Clinton's likely loss coupled with Obama's liberal leanings, it's quite possible some of her more moderate supporters might switch to McCain, but not enough to shake up the election.
If Obama can line himself up with Clinton and line McCain up with the Bush administration, he'll have a better chance of winning over the working class, according to the experts.
"The associations with George Bush are just too devastating for them to cross party lines at this point," Peffley said.
Clinton's populist message is tailor-made for the working class, and many of those voters have fond memories of her husband's presidency.
Voters tend to judge candidates by looking to the past, Voss said, and the economic performance of the country in the Clinton years is still fresh on voters' minds.
Voss said Obama needs to stress the "economic populism underlying his political agenda."
Obama has "put together a fairly progressive political agenda, so he'll be able to explain how the policies he endorses will help take some of the bite out of the current economic troubles for white, working-class voters," he said. "As he educates about his policies, a lot will float into his camp."
In addition to get voters behind his policy and plans, Obama needs to get them behind him as person, Peffley said.
"Obama needs to tell his story. He rose from humble origins. He's not a silver-spoon liberal," he said.
If voters can embrace Obama as a person, they'll be more inclined to embrace him as a politician, the experts said.
White, working-class voters usually have trouble with Ivy League-educated lawyers regardless of their race, Voss said. Just as Bill Clinton was able to overcome that, Obama will need to do the same thing, he said.
As some question whether Obama will be able to pick up the working class should he become the nominee, he already has the vote of confidence from their favorite candidate.
Speaking to her cheering supporters in Kentucky on Tuesday, Clinton assured voters that her party would come together once there's a nominee.
"While we continue to go toe-to-toe for this nomination, we do see eye-to-eye when it comes to uniting our party to elect a Democratic president in the fall," she told an audience in Louisville.