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

Democrat Barack Obama's three decisive wins over rival Hillary Clinton propelled him on Wednesday into the next round of presidential contests on a wave of momentum and sent her scrambling to find an answer.

Obama and Republican front-runner John McCain cruised to victories in Virginia, Maryland and the District of Columbia on Tuesday, with McCain moving closer to clinching his party's nomination for the November election.

Obama extended his hot streak to eight consecutive wins over Clinton in a hard-fought presidential campaign that appears to be tipping his way. The victories allowed Obama to expand his lead in pledged convention delegates, who will select the Democratic Party's nominee at its August convention.

"This is the new American majority," Obama told supporters in Madison, Wisconsin, where the next showdown occurs in a week. "This is what change looks like when it happens from the bottom up."

Clinton, whose deputy campaign manager resigned in her latest staff shake-up, already was counting on contests in Ohio and Texas in three weeks as her best hope to stop Obama's surge.

"We're going to sweep across Texas in the next three weeks," Clinton said in El Paso, Texas, where she headed on Tuesday before the day's results were known. She made no mention of the three contests she lost.

McCain's wins over his last major challenger, former Arkansas Gov. Mike Huckabee, had him looking toward a general election match-up with the Democrats despite continued qualms among conservatives about his views on immigration, tax cuts and other issues.

"We do not know for certain who will have the honour of being the Democratic Party's nominee for president. But we know where either of their candidates will lead this country, and we dare not let them," McCain, an Arizona senator, told supporters in Alexandria, Virginia.

All three of Obama's wins on Tuesday occurred in fertile territory for him, featuring large populations of the highly educated, high-income and black voters who have favoured the Illinois senator.

OBAMA EXPANDS SUPPORT

But exit polls indicated Obama dramatically expanded his support and cut into Clinton's core groups. Obama led among women, Hispanics, seniors and in every income and education level in Virginia and essentially split the white vote with Clinton.

Obama already had edged past Clinton in the race for pledged delegates who formally select a party nominee at a convention in August. A total of 168 Democratic delegates were at 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 needed to clinch the Democratic nomination.

"Tonight, we're on our way," Obama said. "But we know how much 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 longer say our hope is false."

Clinton's latest staff defection was deputy campaign manager Mike Henry. He was brought into the campaign by Patti Solis 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 Clinton skip the kick-off Democratic contest in Iowa. Clinton did not follow his advice and finished third.

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

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

But exit polls showed McCain still had difficulty winning over conservatives. Those who described themselves as very conservative accounted for about one-third of Virginia Republican voters, and two-thirds of those went for Huckabee.

Huckabee, a Baptist minister whose rise has been fueled by strong support from religious conservatives, said he would keep pushing in the race.

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