US. Senator Barack Obama has taken the lead oven Senator Hillary Clinton in early returns from the Democratic Party presidential caucus in the northeastern US State of Maine.
Sunday evening, with 59 percent of the polling places reporting, Obama led Clinton 57 percent to 42 percent.
Clinton and Obama are competing in a closely-matched contest to represent their party in the November general election.
Clinton replaced her campaign manager Sunday, following Obama's victory Saturday
in four out of four contests.
The Clinton campaign said Maggie Williams, a long-time aide to Clinton, will take up the duties of Campaign Manager Patty Solis Doyle later this week.
Obama won primary elections or caucuses in the states of Louisiana, Nebraska and Washington and the territory of the US Virgin Islands. All four victories were by margins of 20 percentage points or greater.
Senator Clinton still has a slim lead in the tally of delegates needed to secure to the Democratic nomination for November's general election.
In contests for the Republican Party nomination, former Arkansas Governor Mike Huckabee dealt surprising defeats in Louisiana and Kansas to the frontrunner, Arizona Senator John McCain.
McCain captured a slim victory in Washington state and still has a sizeable lead in the overall delegate count.
In an interview on CBS television Sunday, Huckabee said his campaign is energized and he may stay in the race through the Republican convention.
Candidates from both parties face off Tuesday in (the eastern states of) Virginia and Maryland, and the U.S. capital of Washington,DC