Obama rolls to three big U.S. wins

WASHINGTON (Reuters) - Barack Obama easily won three 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, Marylandand the District of Columbia, running his hot streak to eightconsecutive wins and expanding his lead in pledged conventiondelegates who select the party's nominee.

"Tonight, we're on our way. But we know how much further wehave to go," Obama told supporters in Madison, Wisconsin, wherethe next showdown occurs in a week. "We know our road will notbe easy. But we also know that at this moment the cynics can nolonger say our hope is false."

Republican front-runner John McCain also swept to wins overhis last major challenger, former Arkansas Gov. Mike Huckabee,in the U.S. capital area contests as he moved closer toclinching the party's nomination for the November election.

McCain already was looking forward to a general electionmatch-up with the Democrats after Tuesday's wins, which willincrease pressure on Huckabee to give up his White House quest.

"Now my friends comes the hard part, and for America, themuch bigger decision," McCain, an Arizona senator, toldsupporters in Alexandria, Virginia.

"We do not know for certain who will have the honour ofbeing the Democratic Party's nominee for president. But we knowwhere either of their candidates will lead this country, and wedare not let them," he said.

The wins for Obama, who would be the first black U.S.president, followed big weekend triumphs in Maine, Louisiana,Nebraska, Washington and the Virgin Islands.

All three of Tuesday's contests occurred in fertileterritory for Obama, with large populations of the highlyeducated, high-income and black voters who have favoured theIllinois senator.

But exit polls indicated Obama dramatically expanded hissupport and cut into Clinton's core groups. Obama led amongwomen, Hispanics and lower-income voters in Virginia andessentially split the votes of whites with Clinton. InMaryland, he captured seniors and rural voters.

"This is the new American majority," Obama said. "This iswhat change looks like when it happens from the bottom up."

Obama already had edged past Clinton in the race forpledged delegates who formally select a party nominee at aconvention in August. A total of 168 Democratic delegates wereat stake in Tuesday's voting.

Obama had 1,017 pledged delegates to Clinton's 942,according to a count by MSNBC -- well short of the 2,025 neededto 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 toprival former Massachusetts Gov. Mitt Romney.

McCain had won 785 of the 1,191 delegates needed fornomination -- an overwhelming lead on Huckabee, who had 240.

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.

"We march on," Huckabee said on Fox News Channel. "We liveto fight another day."

Clinton, a New York senator and wife of former PresidentBill Clinton, has voiced confidence about her campaign's futurebut looked past Tuesday's contests and next week's battles inWisconsin and Hawaii to focus on crucial March 4 votes in thebig 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/)