WASHINGTON — Barack Obama moved inexorably closer to the Democratic presidential nomination Tuesday, holding on to his lead as time runs out on challenger Hillary Clinton.
His decisive win in North Carolina, even as he trailed narrowly in Indiana late into the night, denied her the two-state knockout punch that would have left him reeling.
Tuesday's votes were the last in states big enough to give one of the candidates a game-changing boost in delegates or popular vote. Instead, they now head to six final contests in such smaller venues as West Virginia, Kentucky, Oregon, Puerto Rico, Montana and South Dakota.
With only 217 delegates at stake in all six combined, Obama is all but certain to emerge after five months of voting with his lead among pledged delegates intact. In fact, Obama aides Tuesday night predicted he would win a majority of the pledged delegates this month.
He also added to his nationwide lead Tuesday in the popular vote — a second strong argument to take in June to the party elites who'll cast the deciding convention votes for a nominee.
Obama has one continuing weakness, however, that was reinforced in both Indiana and North Carolina — his inability to win working-class whites. He lost that bloc in both states as a large number of voters signaled that they remained concerned about his ties to his former pastor, the Rev. Jeremiah Wright. Those who thought it was an important story broke solidly for Clinton.
Obama has not won the white vote since videos of Wright damning the United States exploded onto YouTube and TV screens.
That's likely Clinton's last, best hope to convince party superdelegates that Obama is a weak candidate for the fall, that he'll have trouble holding the working-class white vote in battleground states such as Ohio and Pennsylvania.
One prominent neutral Democrat said Tuesday evening that Obama was pulling away for the nomination — but still had to find a way to win white voters both for the sake of the nomination and for the general election.
"The Obama campaign still has a challenge closing this margin with white ethnic and white working-class voters," said Harold Ford Jr., a former Democratic member of Congress from Tennessee.
Yet even with that challenge for Obama, he appeared Tuesday to stop Clinton's improbable comeback and regain the front-runner footing that he'd enjoyed in January and February before stumbling in March and April.
Time and math once again appear to be on his side for clinching the nomination.
First, it's important to remember that neither candidate will win enough delegates in the primaries to clinch the nomination. Each will fall short of the 2,025 necessary.
Rather, they'll have to make their cases to the remaining 200 or so party insiders who get convention votes as "superdelegates" and get to vote how they like regardless of the primary or caucus results in their states.
Ultimately looking for a winner who can defeat the Republicans in November, those superdelegates will look at which candidate won the most primary delegates, which won more popular votes and how each did with key voting blocs.
With only four weeks left of voting, and only 217 delegates left to be awarded in the six contests, Obama has an insurmountable lead among pledged delegates needed to win the nomination.
He led Clinton by 137 delegates even before Tuesday results were counted, a count likely to add to his lead.
That means she would need to win 64 percent of the remaining primary delegates to pull ahead of him in that measure — something next to impossible under party rules.
She's also run out of big states to run up big numbers in the popular vote.
He added to his lead in the nationwide popular vote Tuesday, winning North Carolina by 211,000 votes with most precincts counted, while trailing in Indiana by about 40,000.
That put him ahead in the popular vote under any scenario — including adding disputed results from Michigan and Florida, according to counts tallied by realclearpolitics.com. His margins ranged from 51,000 to 784,000, depending on which states are counted. (Some caucus states don't release official vote counts but estimates are available.)
Clinton's one hope is that superdelegates would see weakness in Obama's continuing problem in winning over whites.
He lost the white vote in both Indiana and North Carolina Tuesday by margins of about 3-2.
The reason could be race, or class, or the appeal of Clinton's populist economic message.
But the effect is the same — that some Democrats refuse to support him and may refuse to support him in November against Republican Sen. John McCain of Arizona as well.
"I've always voted Democrat, but I wouldn't vote for him," said Sherry Richey, a Democrat from Kokomo. "He's a radical. ...He's too un-American."
Some also mentioned the economy, worried about factories slated for closing a year or two down the road and thinking Clinton has more specific proposals to help them.
"She has specific ideas on what she plans to do. You hear her itemize it, 1-2-3, energy, gas prices, jobs, the economy," said Judy Witherow, a fifth-grade teacher from Sharpsville, Ind.
Ford, the former congressman who narrowly lost a Senate race in 2006, said money worries and message, more than race, is driving those white working-class voters to Clinton and away from Obama.
"When the campaign was focused on Iraq, Barack was at an advantage. As it shifted to focus more on the economy, on food and energy prices, Obama has not found as much traction as she has," said Ford.
"Her message is a strong message. Her narrative that Barack is more of speaker than doer, that's resonating with these voters. I ran for the U.S. Senate in a state predominantly made up of that voting bloc. I don't think that bloc is hostile to me or any African-Americans."