( BBC ) - Illinois Senator Barack Obama is projected to win the Democratic caucus in Maine, defeating Hillary Clinton.
The Maine contest tops a weekend of gains by Mr Obama in the battle for the party's presidential nomination.
On Saturday, Mr Obama won in polls Louisiana, Nebraska and Washington state and the US Virgin Islands.
The clean sweep of all five weekend contests puts him almost neck-and-neck with Hillary Clinton in their deadlocked nomination battle.
Meanwhile, Mrs Clinton has appointed a new campaign manager after this weekend's setbacks.
Maggie Williams, who was the New York senator's chief of staff when her husband was serving as US president, will take over from Patty Doyle, who has decided to step down.
Campaign aides said Ms Doyle's decision was not urged upon her by Mrs Clinton or any senior members of her team, the Associated Press reports.
Mr Obama and Mrs Clinton now head into a series of contests on Tuesday: Virginia, Maryland and the District of Columbia.