Sen. Barack Obama swept the Louisiana primary and caucuses in Nebraska and Washington state, slicing into Sen. Hillary Rodham Clinton's slender delegate lead in their historic race for the Democratic presidential nomination. The Illinois senator also won caucuses in the Virgin Islands on Saturday, completing his best night of the campaign. "Today, voters from the West Coast to the Gulf Coast to the heart of America stood up to say 'yes we can"' Obama told a cheering audience of Democrats at a party dinner in Richmond, Virginia. He jabbed simultaneously at Clinton and Republican nominee-in-waiting Sen. John McCain, saying the election was a choice between debating McCain "about who has the most experience in Washington, or debating him about who's most likely to change Washington. Because that's a debate we can win." Obama's winning margins were substantial, ranging from roughly two-thirds of the vote in Washington state and Nebraska to nearly 90 percent in the Virgin Islands. With returns counted from more than one-third of the Louisiana precincts, he was gaining 53 percent of the vote, to 39 percent for the former first lady. As in his earlier Southern triumphs in Alabama, Georgia and South Carolina, Obama, a black man, rode a wave of African-American support to victory in Louisiana. In all, Saturday's four Democratic races offered 161 delegates. In initial allocations, Obama had won 31, Clinton nine. In overall totals in The Associated Press count, Clinton had 1,064 delegates to 1,029 for Obama. A total of 2,025 is required to win the nomination at the national convention in late August in Denver. The Democrats' race was as close as the Republicans' was not, after a slew of Super Tuesday contests failed to provide any clarity in their battle and made it likely they will continue their duel until their party's nominating convention in August. The three state races Saturday, as well as the minor competition in the Virgin Islands, are exceedingly important in helping separate two candidates who have traded barbs and wins from the outset in a tense showdown between a black man and a woman for the party's White House nomination. In the first Republican race Saturday, preacher-turned-politician Mike Huckabee snatched a victory in Kansas' caucuses from John McCain, reflecting the difficulty the veteran senator faces in wooing the party's core conservative bloc despite being virtually assured the nomination after a stellar showing in "Super Tuesday" races on February 5 that drove his chief rival Mitt Romney out of the race. Huckabee secured nearly 60 percent of the Kansas caucus vote a few hours after telling conservatives - his key supporters - he still believes in miracles. He won all 36 delegates at stake for a new total of him 234. But, despite his brave talk, he was hopelessly behind McCain with his 719 delegates out of a total 1,191 needed to secure the Republican nomination. The Democrats' race was as close as the Republicans' was not, after a slew of Super Tuesday contests failed to provide any clarity in their battle and made it likely they will continue their duel until their party's nominating convention in August. The three state races Saturday, as well as the minor competition in the Virgin Islands, are exceedingly important in helping separate two candidates who have traded barbs and wins from the outset in a tense showdown between a black man and a woman for the party's White House nomination. Clinton made no mention of the night's contests as she appeared at a Democratic Party dinner in Virginia, site of one of three primaries this Tuesday. Instead, she criticized McCain, the Republican nominee in all but name. "We have tried it President Bush's way," she said, "and now the Republicans have chosen more of the same." She left quickly after her speech, departing before Obama's scheduled arrival. But his supporters made their presence known, as chants of "Obama" floated up from the audience as she made her way offstage. Preliminary results of a survey of voters leaving their polling places in Louisiana showed that nearly half of those casting ballots were black. As a group, African-Americans have overwhelmingly favored Obama and helped him to win in some earlier primaries. One in seven Democratic voters and about one in 10 Republicans said Hurricane Katrina had caused their families severe hardship from which they have not recovered more than two years later. There was another indication of the impact the storm had on the state. Early results suggested that northern Louisiana accounted for a larger share of the electorate than in the past, presumably the result of the decline of population in the hurricane-battered New Orleans area in the south. McCain cleared his path to the party nomination earlier in the week with a string of Super Tuesday victories and the decision by Romney, a former Massachusetts governor, to suspend his campaign. He spent the rest of the week trying to reassure skeptical conservatives that he was not the political maverick they believed him to be. At the same time party leaders quickly closed ranks behind him. His Kansas defeat aside, McCain also suffered a symbolic defeat when Romney edged him out in a straw poll at the Conservative Political Action Conference meeting across town from the White House. "There are only a few states that have voted - 27 have not," Huckabee said earlier Saturday at the CPAC meeting while also vowing to remain in the race until he can win, or his opponent has the delegates to claim the prize. "People in those 27 states deserve more than a coronation, they deserve an election." McCain, a former Vietnam prisoner-of-war and decorated Navy pilot, has tried to highlight his foreign policy and national security experience and cast himself as the sole candidate capable of securing America in a time of continuing threats from terrorism. But the push has not been easy, as evidenced by Huckabee's victory. "It sends a pretty significant signal to John McCain that he's got a lot of work to do to get significant factions of the Republican Party solidly behind him," said Kris Kobach, the Kansas state Republican Party chairman. McCain, who had no campaign events scheduled Saturday, still needs to unite the party behind his candidacy. He scored one win on Friday with an endorsement from former rival Fred Thompson. The former senator and actor was also a favorite of conservatives, but his poor showing in early contests prompted him to drop out of the race. On Saturday, McCain also received an endorsement Saturday from John Bolton, the former US ambassador to the United Nations and a conservative. Clinton and Obama had both campaigned vigorously Washington state. With Clinton and Obama generally in agreement on most issues, Democratic voters are giving careful consideration to which candidate stood the better chance of beating McCain in the November election. Earlier Saturday, the former first lady warned that Democrats will have a hard time running against McCain's "legendary background," and that she, not Obama, is best positioned "go toe to toe" with, and beat, the likely Republican nominee. She called the Arizona senator a friend, but told supporters in Maine that a McCain presidency would be tantamount to a third Bush administration and continuation of the Iraq war. Obama, also campaigning in Maine ahead of Sunday's caucuses with 24 delegates at stake, looked ahead to the general election, criticizing McCain without mentioning his Democratic rival. Part of Clinton's advantage in the delegate race has been her lead among so-called superdelegates, members of Congress and other party leaders who are not selected in primaries and caucuses - and who are also free to change their minds. McCain initially "stood up to George Bush and opposed his first cuts," Obama said. Now the Republican senator is calling for continuing those tax cuts, which grant significant breaks to high-income taxpayers, "in his rush to embrace the worst of the Bush legacy." Including Saturday's contests, 29 of the 50 states already having selected Democratic delegates. Two more - Michigan and Florida - violated party rules by moving their primaries ahead of February 5 and the Democratic National Committee has vowed not to seat any delegates chosen at either of them. Following the weekend contests, Clinton and Obama are focused on an upcoming trio of races Tuesday in Virginia, Maryland and Washington, D.C., - and Clinton in particular was gearing her campaign toward the high-stakes primaries in Ohio and Texas on March 4. Rhode Island and Vermont also vote that day. Republican primaries will also be held in Virginia, Maryland and Washington, D.C., on Tuesday.