Democrat Hillary Clinton shook up her presidential campaign Sunday as her rival Barack Obama edged ahead in the tight race to win nominating delegates with a new resounding win in Maine.
Ahead of the party's nominating vote in the northeastern state -- where Clinton had been hoping to hold her own after an earlier victory in neighboring New Hampshire -- independent poll-tracker RealClearPolitics.com had given her a slim lead in the delegate stake, with 1,123 to Obama's 1,120.
That lead appeared to collapse late Sunday, however, as the state's Democratic party director Arden Manning told AFP that with three quarters of polling precincts reporting, the projected delegate count was 15 for Obama to nine for Clinton.
Reeling from stinging defeats Saturday by margins of two to one in Washington state, Louisiana, and Nebraska, Clinton replaced her campaign manager Patti Solis Doyle with a longtime Clinton insider, Maggie Williams, according to a statement Sunday from the Clinton camp.
The former first lady now faces an uphill struggle, amid a groundswell of support for Obama, ahead of a trio of votes that he is tipped to win in Virginia, Maryland and Washington, DC.
Clinton needs to ride out a tough February, looking ahead to two key primaries on March 4 in Texas and Ohio, delegate-rich states where polls have shown she may expect better support, according to RealClearPolitics.
Wisconsin votes in the meantime, on February 19.
Last week Clinton also drew five million dollars from her own pocket to shore up her campaign, with every vote counting in her neck-and-neck race against Obama.
A candidate needs backing from a total of 2,025 delegates to be formally crowned the Democratic presidential nominee at the party's convention in August, and to stand in the November elections.
Clinton, 60, is on a historic quest to be the first woman in the Oval Office, but Obama, 46, is firing up voters as he bids to be the first black president.
Both candidates were out campaigning Sunday in Virginia, and its Potomac River neighbors, Maryland and the US federal capital, Washington, DC. Obama is favored in all three due to their large African-American populations.
"I have the ability to bring people together," Obama told a roaring crowd at a school gym in Alexandria, Virginia, an affluent suburb of Washington. "If you will vote for me on Tuesday ... we will transform this country."
Usually of little consequence in past primaries, the three Tuesday votes have become key pieces on the electoral chessboard after Clinton and Obama deadlocked in the 22-state Super Tuesday contests.
Virginia is the biggest prize of Tuesday's "Potomac Primary" with 83 delegates, while Maryland has 70, and the US capital, a separate federal district, offers 15.
On the Republican side, John McCain has yet to convince the party's core conservatives, as highlighted when he lost on Saturday in Kansas and Louisiana to Mike Huckabee.
Even though he is the most likely party nominee after main rival Mitt Romney quit the race last week, Baptist minister Huckabee has vowed to fight on despite having little chance of overcoming McCain's huge delegate lead.
"The fact they're blowing against me hardly motivates me to quit," he told reporters in Washington. "It motivates me to play harder."
Analysts say Huckabee's refusal to pull out of the race could deepen the party division between conservatives and Republicans ready to back McCain as the contender most likely to beat the Democratic nominee in the election.
A Vietnam war hero, McCain, 71, has some 724 delegates to 234 for Huckabee. A total of 1,191 are needed for the nomination.
McCain won the Republican caucuses in Washington state, but his narrow victory -- 26 percent against 24 percent for Huckabee -- showed conservatives remain suspicious of him.
President George W. Bush, who defeated McCain for the nomination in 2000, told Fox news on Sunday that he would help his one-time rival if he secures the nomination, saying there was "no doubt in my mind he's a true conservative."
But he added, "I think that if John's the nominee, he has got some convincing to do to convince people that he is a solid conservative."