Clinton vows to stay in the race

By Jeff Mason

HAMMOND, Indiana (Reuters) - Democratic candidate Hillary Clinton on Friday vowed to stay in the White House race, rejecting a fellow senator's suggestion that she pull out to improve their party's chances in November.

"There are millions of reasons to continue this race," New York Sen. Clinton told reporters after Vermont Democratic Sen. Patrick Leahy, a backer of Clinton rival Barack Obama, said it might be time for her to withdraw.

Many political experts believe Clinton will have a hard time defeating Illinois Sen. Obama for the Democratic nomination to run against Republican Sen. John McCain in November's election.

Embarking on a six-day bus tour of Pennsylvania, which holds the next primary on April 22, Obama said the race for the Democratic nomination was "a good movie that lasted about a half an hour too long."

Clinton pounced on the comment. "I like long movies," she said.

Polls show Clinton leading by a wide margin in Pennsylvania but Obama picked up a valuable endorsement from popular Pennsylvania Democratic Sen. Robert Casey. The endorsement could help Obama with Catholics and blue-collar white voters who may otherwise be attracted to Clinton.

Casey said the campaign was a chance for change, new politics and healing. "I believe in my heart that there is one person who is uniquely qualified to lead us in that direction and that is Barack Obama," Casey said in Pittsburgh as Obama stood on stage next to him.

Many Democrats are worried that the increasingly bitter battle between Clinton and Obama can only help McCain who has clinched the Republican nomination. The Arizona senator on Friday aired the first TV ad for the November election.