Sen. Barack Obama easily won Democratic primaries Virginia and Maryland on Tuesday and reached out for another in the District of Columbia in a determined drive to erase Hillary Rodham Clinton's delegate lead in the party's presidential race.
Obama's triumphs made it seven straight over Clinton, the former first lady, now struggling in a race she once commanded.
His Virginia victory left him a scant 10 delegates short of his rival, with 132 left to allocate for the night.
Her deputy campaign manager resigned, the second high-level Clinton departure in as many days.
The Illinois senator was gaining more than 60 percent of the Virginia vote, and Clinton, senator from New York, less than 40 percent.
The Associated Press made its call in the Maryland race based on surveys of voters as they left the polls.
Republican front-runner John McCain won both states, adding to his insurmountable lead in delegates for the GOP nomination.
Interviews with voters leaving the polls in Maryland and Virginia showed Obama split the white vote with Clinton, and his share of the black vote approached 90 percent. She led among white women, but he was preferred by a majority of white men.
Icy roads in Maryland prompted a judge to order a 90-minute extension in voting hours, delaying returns and the allocation of delegates there.
In all, there were 168 delegates at stake in primaries in those states and the District of Columbia.
Overall, Clinton had 1,164 delegates to 1,154 for Obama. Both are far from the 2,025 needed to win the nomination at the Democratic National Convention this summer.
McCain's victory in Virginia was a close one, the result of an outpouring of religious conservatives who backed former Arkansas Gov. Mike Huckabee.
Four in 10 Republican voters said they were born again or evangelical Christians -- twice as many as called themselves members of the religious right in 2000 -- and nearly 70 percent of them supported Huckabee, an ordained Baptist minister.
Virginia voters could vote in either primary in their state. In a twist, Huckabee was running slightly ahead of McCain among independents, who cast about a fifth of the Republican votes there.