Senator Barack Obama has scored three decisive primary victories, Tuesday over Senator Hillary Clinton, winning big in Maryland, Virginia and Washington, DC in the race for the Democratic presidential nomination. On the Republican side, Senator John McCain has also won all three races, though he faced a stronger than expected challenge from former Arkansas Governor Mike Huckabe in Virginia. VOA Correspondent Cindy Saine reports from Washington.

It was a night of triumph for Senator Barack Obama, as he swept the races known as the "Potomac Primary" for the river that flows through the nation's capital. Obama headed to the midwest for his victory rally, speaking to a crowd of about 17,000 people at the University of Wisconsin in Madison.

"We won the state of Maryland, we won the Commonwealth of Virginia, and though we won in Washington, D.C., this movement won't stop until there's change in Washington, D.C. And tonight we're on our way," said Barack Obama.

The three victories came after a string of wins Saturday and Sunday for Obama, putting the 46-year-old African-American in the lead with the largest number of delegates for the first time. But the race is still close. Obama and Clinton each have over 1,000 of the more than 2,000 delegates needed to secure the Democratic nomination.

Senator Clinton made clear she is already looking ahead to the March 4 primaries three weeks from now, in the big and delegate rich states of Texas and Ohio, where she currently has a lead in opinion polls.

She spoke to her supporters in El Paso, Texas.

"Every single one of us knows that tomorrow can be better than today, but it doesn't happen just by wishing it, or hoping for it. It happens by working really, really hard," said Hillary Clinton. "To make it a reality to give everybody a better chance."

Republican John McCain won easily in Maryland and Washington, D.C., but by a lesser margin in Virginia, where evangelical Christians turned out in strong numbers for former Arkansas Governor Mike Huckabee. Speaking to his supporters in Alexandria, Virginia, McCain also took an indirect shot at Obama, who has become famous for his speeches about hope and change.

"To encourge a country with only rhetoric, rather than sound and proven ideas, the trust and the strength and courage of free people is not a promise of hope, it's a platitude," said John McCain.

With his three wins Tuesday, McCain is edging closer to the more than one thousand delegates needed to secure the Republican Party's nomination. But former Governor Mike Huckabee, speaking in his home state of Arkansas, said he is still in the race.

"There are these calls to say let's just call it off," said Mike Huckabee. "Well, that's a disservice to the people in Texas and Ohio and Pennsylvania and North Carolina and Nebraska and other states and territories who have yet to have that opportunity to vote."

The focus now shifts to Wisconsin, where both parties will hold a primary next Tuesday, and to Hawaii, where there will be a Democratic caucus the same day.