FAIRMONT, West Virginia (AFP) - Hillary Clinton looked set to win West Virginia's presidential primary by a landslide Tuesday but unlikely to break Barack Obama's stranglehold on the Democratic nomination. The former first lady, vowing to battle on even as Obama turns his sights on Republican presumptive nominee Senator John McCain, led her foe by 36 points in the latest poll out of the mountainous state. Polling stations opened at 6:30 am (1030 GMT) in the rural, mountainous state that carries the prize of 28 delegates distributed proportionally based on the results of the vote. "West Virginia has a record of picking presidents," Clinton said at a campaign stop here late Monday, as she pressed home her claim that she, and not Obama, was the best Democratic White House pick. "A Democrat doesn't win the White House without winning West Virginia. So tomorrow it's going to be your turn." Clinton said some wanted to call the nomination race over, but "they don't understand politics, because West Virginia really matters." The New York senator was also fairing well in Kentucky, which votes on May 20, where the latest poll said she was up 58pc to 31pc for Obama. Huge wins for Clinton in both states will do little to erode Obama's advantage in the epic Democratic nominating contest, which he leads in every category. But lopsided losses in the two states could underscore Obama's struggle to win over white, working-class voters, which could be a problem in November's election. Arizona Senator McCain and Obama are increasingly firing the early shots in the general election campaign. In a major speech on global warming Monday, McCain sharply broke with his fellow Republican Bush on climate change, in a strategy that also had one eye on independent voters who are worried about the environment. The Obama campaign has launched a 50-state voter registration drive and both sides are trying to woo independent voters, plotting battle plans to be rolled out as soon as the Democratic race is over. Highlighting his growing focus on the election, Obama laid plans to campaign on Tuesday in November swing state Missouri and on Wednesday in Michigan, after stops in West Virginia and Kentucky. A potential complication to McCain's White House bid emerged with the news that former Republican congressman Bob Barr, 59, plans to run for president on the Libertarian Party's ticket. Barr, who played a key role in the congressional impeachment of former president Bill Clinton, said there was not "currently or anywhere on the horizon" any candidate who understood the need for fiscal conservatism and America's founding principles. He added that if McCain fails to win the presidency, "it will be because Senator McCain did not present, and his party did not present, a vision, an agenda, a platform and a series of programs" for the American people. Clinton meanwhile poured her energy into one last day's campaigning in West Virginia. A Suffolk University poll had Clinton leading Obama by 60 percent to 24 percent in the rural coal-mining state, which is one of America's poorest. In a Herald-Leader/WKYT Kentucky Poll of probable Democratic voters, Clinton led by 58 percent of 31 percent, though the survey showed either Democrat would have a tough task beating McCain in the state in November. Clinton trails Obama in Democratic delegates, nominating contests won and the popular vote, with only six more contests left in the grueling primary season. She has also lost her lead in superdelegates, the party officials who will likely decide the nomination. Neither Clinton nor Obama can now reach the nominating threshold of 2,025 delegates on pledged delegates alone. Obama added at least four more superdelegates to his tally on Monday. According to independent website RealClearPolitics, he leads Clinton by 279 superdelegates to 272, and in total delegates by 1,870 to 1,698.