Barack Obama took a stride towards the Democratic Party's presidential nomination with victory over Hillary Clinton Tuesday in North Carolina, according to US media projections.
But CBS News said the former first lady was on course to win in Indiana, the other state holding its primary on Tuesday. Other US networks said Clinton was ahead in the midwestern state, but the outcome was too early to call.
"This is a big win in North Carolina for the Obama camp," Missouri Senator Claire McCaskill, an Obama supporter, told MSNBC.
"The math is inescapable at this point and the superdelegates keep coming to our side regardless of what happens," she said, referring to nearly 800 Democratic grandees who look set to decide the nomination.
The two states were the biggest nominating contests left in the Democrats' White House tussle after months of back and forth that will culminate in the final primaries on June 3.
A likely split of the two states would probably send the rivals into the last six contests locked in bitter stalemate, raising the prospect of a prolonged battle for the nomination which could open deep rifts in the party.
CNN exit polls said the African-American Obama, buffeted by weeks of controversy over racially tinged remarks by his former pastor, had won more than one-third of white voters in North Carolina.
Clinton meanwhile had her sights set on a "game-changer" that could inject fresh momentum into her long-shot comeback hopes. With just over 40 percent of the vote counted in Indiana, she was up 56 percent to 44 percent for Obama.
Loud boos rang from the crowd at Clinton's election night party in Indianapolis, Indiana, as the TV networks projected North Carolina for Obama.
Exit polls for US media organizations showed the worsening US economy was the biggest concern of voters, pushing the war in Iraq into a distant second place.
The exit surveys suggested that 65 percent of Indiana voters believed Obama shared their values, a boost to the Illinois senator after the furore surrounding his fiery pastor, Reverend Jeremiah Wright.
A total of 187 pledged delegates were on offer in the two states -- 115 in North Carolina and 72 in Indiana. After Tuesday, 217 elected delegates were be up for grabs in the remaining six contests ending in early June.
Clinton's camp admits she cannot overtake Obama in the count of pledged delegates who will formally anoint the nominee at the Democratic convention in August.
So she is trying to persuade the superdelegates, who are free to vote for either candidate, that her inexperienced rival would go down in flames against Republican John McCain in November's general election.
Clinton refused to say whether she would pull out of the race if she lost both contests. "I don't make predictions," she said, as she toured the famed Indianapolis Motor Speedway with Indy 500 driver Sarah Fisher.
"Life is unpredictable, racing is unpredictable, politics is unpredictable."
Obama, who needed a good showing to shake off a grim few weeks, was again up before dawn, after shaking hands at a shift change in an auto manufacturing plant in Indiana until past midnight on Monday.
"I think it's going to be close. I don't think anybody knows exactly what's going to happen," he said, holding two campaign stops in Indiana, before heading to North Carolina for what he hoped would be a victory party.
Clinton meanwhile raised the prospect of carrying on after the end of the nominating calendar, a scenario many Democrats fear could split the party and hand victory to McCain.
Looking ahead to June, she said "if we haven't done it already, we are going to have to resolve Florida and Michigan. They were legitimate elections, people came out and voted."
She said the true finish line of the presidential race was 2,209 delegates -- including Florida and Michigan, whose pro-Clinton results were voided in an argument with Democratic bosses about the timing of the states' primaries.
Obama's campaign says he is now only 273 votes short of the long-assumed winning line of 2,025 delegates, and will be closer still after his North Carolina triumph.
Contradicting Clinton, Democratic National Committee chairman Howard Dean said the target remained 2,025.
"There's going to be a compromise is what I would predict," he said on MSNBC, ahead of a May 31 meeting of the DNC's rules committee on the Florida-Michigan headache.
"We'll have a nominee by the end of June," Dean added, playing down fears of a convention brawl in August.
