Many Republicans say they have the greater burden. Arizona Senator McCain, 72, is ``either tied or behind in every swing state,'' says John Weaver, a former top adviser. ``It's an uphill battle, cobbling together 270 electoral votes.''
Young Voters
The use of the Internet and text-messaging may drive the outcome, particularly among the young voters who have been among Obama's most enthusiastic backers. The question is whether they will come to the polls in large numbers in November; if they do, it would be the first time since the voting age was lowered to 18 in 1972 that they will substantially affect the result.
Obama's campaign is conducting a massive voter-registration drive. Steve Hildebrand, his deputy campaign manager, says three states -- Florida, Michigan and North Carolina --- have more than 400,000 new voters; Georgia and Pennsylvania have more than 300,000. Most of the new voters favor Obama, he says.