Barack Obama is out in front of Hillary Rodham Clinton for the first time in the race for Democratic delegates.
Obama got a boost from newly released results from Saturday's Washington state caucus, and he extended it with wins Tuesday in Virginia, Maryland and the District of Columbia.
Obama won at least 51 delegates Tuesday night, with 93 still to be awarded. Clinton won at least 24.
According to an Associated Press analysis of caucus results released by the state party Tuesday night, Obama won 53 of Washington state's 78 delegates and Clinton won 25.
In the overall race for the nomination, Obama has 1,212, including separately chosen party and elected officials known as superdelegates. Clinton has 1,191.
On the Republican side, John McCain picked up 60 delegates from winning the Virginia primary to widen his lead over Mike Huckabee. McCain also won primaries in Maryland and Washington, D.C.