Obama on a roll after three big U.S. wins

WASHINGTON (Reuters) - Democrat Barack Obama's threedecisive wins over rival Hillary Clinton propelled him onWednesday into the next round of presidential contests on awave of momentum and sent her scrambling to find an answer.

Obama and Republican front-runner John McCain cruised tovictories in Virginia, Maryland and the District of Columbia onTuesday, with McCain moving closer to clinching his party'snomination for the November election.

Obama extended his hot streak to eight consecutive winsover Clinton in a hard-fought presidential campaign thatappears to be tipping his way. The victories allowed Obama toexpand his lead in pledged convention delegates, who willselect the Democratic Party's nominee at its August convention.

"This is the new American majority," Obama told supportersin Madison, Wisconsin, where the next showdown occurs in aweek. "This is what change looks like when it happens from thebottom up."

Clinton, whose deputy campaign manager resigned in herlatest staff shake-up, already was counting on contests in Ohioand Texas in three weeks as her best hope to stop Obama'ssurge.

"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.

McCain's wins over his last major challenger, formerArkansas Gov. Mike Huckabee, had him looking toward a generalelection match-up with the Democrats despite continued qualmsamong conservatives about his views on immigration, tax cutsand other issues.

"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," McCain, an Arizona senator, told supportersin Alexandria, Virginia.

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

OBAMA EXPANDS SUPPORT

But exit polls indicated Obama dramatically expanded hissupport and cut into Clinton's core groups. Obama led amongwomen, Hispanics, seniors and in every income and educationlevel in Virginia and essentially split the white vote withClinton.

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 1,074 pledged delegates to Clinton's 967,according to a count by MSNBC -- well short of the 2,025 neededto clinch the Democratic nomination.

"Tonight, we're on our way," Obama said. "But we know howmuch further we have to go. We know our road will not be easy.But we also know that at this moment the cynics can no longersay our hope is false."

Clinton's latest staff defection was deputy campaignmanager Mike Henry. He was brought into the campaign by PattiSolis Doyle, who stepped down as campaign manager 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.

In the Republican race, McCain has built a nearlyinsurmountable lead in delegates to the party's nominatingconvention and became the likely nominee last week with thewithdrawal of top rival former Massachusetts Gov. Mitt Romney.

McCain has won 801 of the 1,191 delegates needed fornomination while Huckabee has 240.

But exit polls showed McCain still had difficulty winningover conservatives. Those who described themselves as veryconservative accounted for about one-third of VirginiaRepublican voters, and two-thirds of those went for Huckabee.

Huckabee, a Baptist minister whose rise has been fueled bystrong support from religious conservatives, said he would keeppushing in the race.

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

(Additional reporting by Andrew Stern, Caren Bohan; Editingby Bill Trott)

(To read more about the U.S. political campaign, visitReuters "Tales from the Trail: 2008" online athttp://blogs.reuters.com/trail08/)