WASHINGTON (CNN) -- While Sen. John McCain was inching toward the Republican presidential nomination, Sen. Barack Obama staked a claim as the Democratic front-runner.

Obama's wins in the District of Columbia, Maryland and Virginia primaries propelled him past Sen. Hillary Clinton in the race for delegates.

According to CNN calculations, Obama has 1,215 delegates to Clinton's 1,190.

To clinch the Democratic nomination, a candidate must get 2,025 delegates.

Obama had led in pledged delegates, but Clinton had held the lead when superdelegates were factored in.

Superdelegates, a group of almost 800 Democratic Party officials and leaders, are not required to make their votes public and are free to change their minds.

The Illinois senator has now won eight consecutive contests.

McCain, the presumptive nominee for the Republican party, has 812 delegates to former Arkansas Gov. Mike Huckabee's 217, according to CNN estimates. See CNN's political team analyze Tuesday's results »

A GOP candidate needs 1,191 delegates to secure the nomination.

"The change we seek swept through Chesapeake and over the Potomac," Obama told supporters Tuesday night.

"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 is change in Washington, D.C., and tonight we're on our way." Watch Obama rally supporters »

McCain saluted Huckabee after the results came in but turned his campaign toward the general election, saying he would offer "a better understanding of the challenges we face" than either of the Democratic front-runners.

"We know where either of their candidates will lead this country, and we dare not let them," the Arizona senator said, without mentioning the Democratic candidates by name. Watch McCain talk about what's ahead »

McCain, who has come under criticism from conservatives who say he is too liberal to be the Republican nominee, carried the conservative vote in Maryland, according to exit polls. See what some top conservatives say about McCain »

Huckabee, however, fared better with conservatives in Virginia.

He vowed to stay in the race despite losing three more primaries, pledging to give voters in the coming primaries "a solid, conservative, absolute pro-life candidate" as an alternative to McCain.

"The nomination is not secured until somebody has 1,191 delegates," Huckabee said. "That has not yet happened. We're still continuing to work and to give voters in these states a choice." Watch why Huckabee says he's marching on »

Obama did well with Democrats across race and gender lines Tuesday night, and seems to be eating away at Clinton's backbone of support: women.

According to exit polls out of Virginia and Maryland, Obama won roughly 60 percent of the female vote -- a demographic that has carried Clinton to success in past primaries. Clinton fared worse among men -- more than two-thirds in both states chose Obama.

Meanwhile, Obama scored his highest percentage of African-American support to date, winning close to 90 percent of that voting bloc in each state.

The two evenly split the white vote in Virginia, while Clinton slightly beat Obama among whites in Maryland.

In most past primaries, Clinton has held an edge among white voters. Tuesday, Obama even beat Clinton among Latino voters, a group that has heavily favored Clinton in most past primaries.

In Virginia and Maryland, Latinos went for Obama over Clinton by 6 points, though their support was not decisive in either contest -- only 5 percent of Democratic primary voters in Virginia and 4 percent in Maryland were Latino.

The only demographic Clinton won was white women, who broke for her over Obama by 10 points in Virginia and 13 points in Maryland.

Clinton turned her attention to Texas, which holds its primary on March 4.

"We're going to sweep across Texas in the next three weeks, bringing our message about what we need in America ... I'm tested, I'm ready. Let's make it happen," the New York senator told a crowd in El Paso. Watch Clinton campaign in Texas »

Candidates from both parties face off again next Tuesday in Wisconsin and Washington, and Hawaii holds its Democratic caucuses then.

March 4 is another delegate-rich day, with contests in Ohio, Rhode Island, Texas and Vermont.

McCain needs 379 more delegates to clinch his party's nomination. E-mail to a friend

CNN's Paul Steinhauser, Alexander Mooney and Erik Tavcar contributed to this report.

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