Tampa, Florida:
US President Barack Obama set out to block Mitt Romney's road to the White House on Thursday on the second day of a non-stop 40 hour blitz of states that will decide the election.
Mr Obama landed in balmy Florida before dawn after a flight across three time zones, following a late night rally in Las Vegas and a trip into the bowels of Sin City's plush Bellagio casino hotel to rally union workers.
The president was appearing in Florida, Virginia and Ohio, and if he can win just one of those three key swing states, and pick up a few smaller battlegrounds, he could all but assure himself of a second four year term.
"I have come to Florida today to ask for your vote," Mr Obama told a loud crowd of 8,500 people who gathered in Tampa despite the early hour.
"We have come too far to turn back now," said Mr Obama, his voice raspy with fatigue.
Averages of recent polls have shown Republican nominee Mr Romney may be up slightly in Florida and Virginia, which Mr Obama, in 2008, was the first Democrat to win since 1964, but the president appears to have a consistent edge in Ohio.
Republican Mr Romney knows the stakes in Ohio, no Republican has been elected president without the rust belt battleground and was spending the whole day in the state
Twelve days from the election on November 6, Mr Obama got a symbolic boost in the neck-and-neck race, securing the endorsement of former Republican secretary of state Colin Powell.
"I voted for him in 2008 and I plan to stick with him in 2012, and I'll be voting for him and for Vice President Joe Biden next month," Mr Powell told CBS "This Morning".
Mr Powell traced recent improvements in the economy to Mr Obama and praised him as a steely commander-in-chief.
"I also saw the President get us out of one war, start to get us out of a second war and did not get us into any new wars.
"I think that the actions he's taken with respect to protecting us from terrorism have been very, very solid."
Another political heavyweight also stepped up his support for the incumbent Democrat: popular former president Bill Clinton announced plans to campaign with Mr Obama in Florida on Monday.
Mr Obama campaigned into the late hours on Wednesday night in Nevada, after visiting Iowa, Colorado and California, all before jumping aboard Air Force One for a "red eye" flight to Florida.
On NBC's "Tonight with Jay Leno" Mr Obama jabbed old antagonist Donald Trump, who revived the conspiracy theory over his birthplace.
"This all dates back to when we were growing up together in Kenya," joked Mr Obama, who was born in Hawaii to a Kenyan father and a white American mother.
"When we finally moved to America, I thought it would be over," the president said with a beaming grin, though he admitted that, in reality, he had never met the flamboyant property mogul.
Mr Trump earlier offered to pay $5 million to a charity of Mr Obama's choice if the president would release his college records and passport applications, as he continued to press his case that Mr Obama's past hides embarrassing secrets.
Mr Romney was also on the trail in the battleground states on Wednesday, appearing in Reno, Nevada and Iowa, again seeking to build an impression that his recent polling surge can be sustained in the final days of the campaign.
"The Obama campaign is slipping because it can't find an agenda to help the American families," Mr Romney said.
"I'm optimistic. I'm optimistic, not just about winning, we are going to win by the way" Mr Romney said.
But Mr Romney again saw his hopes of leveling a devastating attack on the president's economic record frustrated by another row over the Republican Party's attitude to women's health issues and abortion.
Republican Senate candidate Richard Mourdock said that pregnancy caused by rape was "something God intended to happen" offering an opening for the Obama campaign, which said Mr Romney backs 1950s-style social policies.
"I don't think any politician in Washington, most of whom are male, should be making health care decisions from women. Women can make those decisions themselves," Mr Obama said to a large cheer in Tampa.
On Wednesday, he told Mr Leno "rape is rape. It is a crime."
The row put Mr Romney in an awkward spot with women voters, who already back Obama in larger numbers and whose support could prove decisive in knife-edge state races on November 6.
But Mr Romney is also wary of alienating evangelical voters and social conservatives, who oppose abortion as an article of faith and who form an important part of his base in battlegrounds like Ohio.
Later on Thursday, Mr Obama will head to Illinois to cast his own early vote, before ending his tour with an evening rally in Ohio.