President Obama on sleepless tour while Mitt Romney stays in Ohio

Although national polls show the race is close, Romney is struggling to overtake Obama in the state-by-state march to racking up the 270 Electoral College votes needed for victory. Romney has far fewer paths to reaching that threshold than Obama, who starts with more states — and more Electoral College votes — in his win column. The race is centered on just nine states, where polls show competitive races: Ohio, Florida, Iowa, New Hampshire, Virginia, North Carolina, Colorado, Nevada and Wisconsin.

The president's morning rally kicked off the second day of his 40-hour battleground state blitz. After spending the night on Air Force One en route to Florida, he was heading to Virginia, Illinois and Ohio before returning to the White House.

Shortly after 7 a.m. and less than five hours after ending his day in Las Vegas, Obama was at a Krispy Kreme doughnut shop near downtown Tampa, and minutes later delivered the still warm doughnuts to a nearby firehouse. He said he wanted to come by early — noting he is not often out this early — to thank them for all they do.

Obama then spoke to about 8,500 people at a morning rally in Tampa, a swing area of battleground state Florida.

With a full day of campaigning still ahead of him, Obama's voice was already hoarse. But he told the enthusiastic crowd he was "just going to keep on keeping on until every single person out there who needs to vote is going to go vote."

He noted to cheers that he was going to Chicago later Thursday to participate in early voting and that first lady Michelle Obama already mailed in her ballot. Obama campaign spokesman Jennifer Psaki said they hoped his example would send a message to others in early voting states that they should do so as well.

Obama's campaign also announced joint rallies Monday with Bill Clinton in Orlando, Fla., Youngstown, Ohio, and Prince William County, Va. The president also picked up an endorsement from former Secretary of State Colin Powell, a Republican who supported Obama in 2008. Powell praised Obama's handling of the economic recovery, telling "CBS This Morning:" ''I think we've begun to come out of the dive and we're gaining altitude." White House spokesman Jay Carney said the president learned of the endorsement while visiting the Tampa fire station and called Powell to thank him.

Pickler reported from Washington. Associated Press writers Steve Peoples and Kasie Hunt in Cincinnati and Julie Pace and Ken Thomas in Washington contributed to this report.