Democratic presidential contender Hillary Clinton is looking for a decisive win in Tuesday's West Virginia primary to keep alive her fleeting hopes of winning the White House this year. VOA National correspondent Jim Malone has more from Washington.

Hillary Clinton has a big lead in West Virginia over rival Barack Obama, but experts say even a decisive Clinton victory there will do little to blunt Obama's momentum for the Democratic Party's presidential nomination.

Clinton remained undaunted by her increasingly long-shot odds of winning the nomination as she rallied supporters on the eve of the primary.

"This is going to be a crucial turning point," Clinton said.

Clinton's campaign spokesman, Howard Wolfson, told NBC television that Clinton intends to remain in the race through the end of the primary season on June 3.

"And I think superdelegates who, as you say, have been moving towards Barack Obama in the last week are going to wake up tomorrow and say, 'you know, I am a little concerned about the fact that our presumptive nominee cannot win West Virginia'," said Wolfson.

The so-called superdelegates are Democratic Party activists and elected officeholders, including members of Congress, governors and big-city mayors, who can vote for either candidate at the national nominating convention.

Obama continues to gain uncommitted superdelegates, including several more this week and now leads Clinton in that category even though she once had a big lead. Obama also holds a lead in the overall delegate count.

Superdelegates will provide the winning margin for the eventual Democratic nominee since neither Obama nor Clinton will win enough delegates outright by early June to claim the nomination.

Obama spent little time campaigning in West Virginia and appears to be shifting his focus away from Clinton to the presumptive Republican nominee, Senator John McCain.

"She is a capable, smart, hard working, intelligent candidate," Obama said. "She has served this country well and whatever the differences between myself and her, they are nothing compared to the differences we have with John McCain."

Senator McCain is also positioning himself for the general election campaign later this year by putting distance between himself and President Bush on the issue of global climate change.

McCain told an audience in Oregon that he would break with the Bush administration and would push for mandatory limits on greenhouse gas emissions if elected in November.

"I will not permit eight long years to pass without serious action on serious challenges," said McCain.

Some Democrats and political experts have voiced concern that the long and bitter Democratic nomination battle between Obama and Clinton could hurt the party's chances in the November election.

But two new public opinion polls found that clear majorities of those surveyed said Clinton should stay in the race for the time being.