Barack Obama has won the Maine caucuses to take all five weekend Democratic contests, gaining new momentum and further narrowing rival Hillary Clinton's delegate lead in their epic battle for the party's presidential nomination.
Even before the loss in Maine, Mrs Clinton, stung by defeats a day earlier in Nebraska, Washington state, Louisiana and the US Virgin Islands, replaced her campaign manager Patti Solis Doyle.
The campaign reshuffle in which Mrs Clinton installed her long-time aide Maggie Williams as her new campaign chief came ahead of the so-called Potomac primaries -- nomination races in Virginia, Maryland and Washington DC that she needs to widen her delegate lead in a deadlocked race that could last until the party's national convention in August.
The two states and the US capital all have sizeable number of black Democratic voters, a constituency that has aided Mr Obama in earlier contests.
In the latest overall totals in The Associated Press count, Mrs Clinton had 1,136 delegates to 1,108 for Mr Obama. The totals include so-called superdelegates, which are party leaders not chosen at primaries or caucuses, free to change their minds.
A total of 2,025 delegates is required to win the nomination at the national convention in Denver, Colorado, in late August.
In Maine, with 95% of the participating precincts reporting, Mr Obama led with 59% of the vote, to 40% for Mrs Clinton. Mr Obama won 15 of Maine's delegates to the national convention and Mrs Clinton won nine.
Mr Obama, who hopes to be the US's first black president, was buoyant after his weekend winning sweep.
He even won a Grammy for his audio version of his book The Audacity of Hope: Thoughts On Reclaiming The American Dream, beating former presidents Bill Clinton and Jimmy Carter in the best spoken word album category.
"I have the ability to bring people together," he said. Because of that, "I think I can beat John McCain more effectively," he said, in a reference that highlighted a shift in both his and Mrs Clinton's campaign aimed at addressing the challenge the presumptive Republican nominee would pose in the November general elections.
