By John Whitesides, Political Correspondent
WASHINGTON (Reuters) - Barack Obama easily won two moreDemocratic nominating contests on Tuesday, extending hiswinning streak over rival Hillary Clinton and building momentumin a hard-fought U.S. presidential race.
Obama rolled to decisive victories in Virginia and theDistrict of Columbia, running his hot streak to sevenconsecutive wins and expanding his lead in pledged conventiondelegates who select the party's nominee.
Republican front-runner John McCain narrowly defeated hislast major challenger, former Arkansas Gov. Mike Huckabee, inVirginia as McCain moved closer to clinching the party'snomination for the November election.
Maryland officials extended voting, which was supposed toend at 8 p.m. EST/0100 GMT on Wednesday, to 9:30 p.m. EST/0230GMT as rain and freezing temperatures created travel hazardsthroughout the region.
Obama, who would be the first black U.S. president, hadbeen favoured in all three of Tuesday's contests after his bigweekend wins in Maine, Louisiana, Nebraska, Washington and theVirgin Islands.
All three contests occurred in fertile territory for Obama,with large populations of the highly educated, high-income andblack voters who have favoured the Illinois senator.
But exit polls in Virginia indicated Obama was cutting intoClinton's core groups of supporters. He led among women,Hispanics and lower-income voters and essentially split thevotes of whites with Clinton, while crushing her 9-to-1 amongblacks -- an even larger margin than usual.
In Virginia, Obama was winning more than 60 percent of thevote with more than two-thirds of the precincts reporting.
Obama has edged past Clinton in the race for pledgeddelegates who formally select a party nominee at a conventionin August. A total of 168 Democratic delegates were at stake inTuesday's voting.
Obama had 958 pledged delegates to Clinton's 904, accordingto a count by MSNBC before Tuesday's voting -- well short ofthe 2,025 needed to clinch the Democratic nomination.
DAUNTING LEAD FOR MCCAIN
Among Republicans, McCain has built a nearly insurmountablelead in delegates to the party's nominating convention andbecame the likely nominee last week with the withdrawal of histop rival, former Massachusetts Gov. Mitt Romney.
McCain had won more than 700 of the 1,191 delegates neededfor nomination heading into Tuesday's voting -- an overwhelminglead on Huckabee, who has barely more than 200. He won another63 by capturing Virginia.
But Huckabee won two of three contests on Saturday asMcCain, an Arizona senator, struggled to win over disgruntledconservatives unhappy with his record on immigration, taxes andother issues.
Clinton, a New York senator and wife of former PresidentBill Clinton, has voiced confidence about her campaign's futurebut looked past Tuesday's three contests and next week'sbattles in Wisconsin and Hawaii to focus on crucial March 4contests in the big states of Texas and Ohio.
"We're going to sweep across Texas in the next threeweeks," Clinton said in El Paso, Texas, where she headed onTuesday before the day's results were known. She made nomention of the three contests she lost.
"I'm tested, I'm ready, let's make it happen," she said.
Clinton was hit by another staff defection with theresignation of deputy campaign manager Mike Henry. He wasbrought into the campaign by Patti Solis Doyle, who steppeddown on Sunday.
Henry, who managed Virginia Gov. Tim Kaine's win in 2005,was the author of a memo last year that recommended Clintonskip the kick-off Democratic contest in Iowa. Clinton did notfollow his advice and finished third.
(Additional reporting by Deborah Charles, Jeff Mason,Andrew Stern, Caren Bohan; Editing by Lori Santos)
(To read more about the U.S. political campaign, visitReuters "Tales from the Trail: 2008" online athttp://blogs.reuters.com/trail08/)
