An exhausted Barack Obama pleaded with the people of Ohio on Friday to erect a "firewall" around their state that could save his presidency, declaring: "I'm not ready to give up the fight." His voice failing even before he embarks on a two-day blitz of swing states on Saturday, Obama told Ohioans that their ballots may be decisive in securing him four more years as the "champion" of the poor and weak.
"I need you, Ohio, to make sure their voices are heard," he rasped to 2,600 supporters packed into a dusty barn on a cold state fairground in Hilliard. "To make sure that no matter who you are or where you came from, you can make it in America."
The president criticised Mitt Romney, his Republican challenger, as an untrustworthy salesman who was resorting to lying in the last gasps of his six-year attempt to secure the White House.
"We know what change looks like," Obama said of Romney's 11th-hour claims to represent a sharply different path for America. "And what the governor is offering ain't it."
While effectively tied with Mr Romney in polls of the national vote, Obama is depending on slim leads in more of the country's swing states to hand him victory in the US electoral college. Polls suggest that Ohio, which has backed every winning presidential candidate since 1960, is again poised to be the "tipping point" in securing the winning candidate the required 270 electoral votes.
Obama's allies point to his year-long lead over Romney in polls of the state, which holds 18 electoral votes, above all other indicators that he will be re-elected on Tuesday. Introducing the president, Ted Strickland, a former governor of Ohio, told voters that preserving Mr Obama's lead - which stands at 2.3% on average - could deny Romney national victory.
"Let me tell you my friends, Ohio will be the firewall," said Strickland, also hoarse. "So between now and the polls closing on November 6, use every ounce of your energy to get out the vote."
In a state where one in eight jobs is linked to vehicle manufacture, Romney has suffered badly from his opposition to Obama's $85?billion (pounds 53?billion) bail-out of the automotive industry. "The bail-out was very controversial but it was the right thing to do," said Harry Andrist, a 69-year-old retiree. "He has consistently made hard choices and shown that he's got the right values".
The president also criticised Romney for a new television attack advertisement in which the Republican falsely claims that Jeep is preparing to ship jobs from the US to China. "It's not true," said Obama. "Everybody knows it's not true. The car companies themselves have asked Governor Romney to knock it off."
The crowd, younger and more diverse than those attracted by Romney, responded with cries of: "He's a liar". They roared with approval at Obama's criticism of the Republican Party's positions on social issues, which have shifted sharply to the Right.
Amina Gaila, 19, a Muslim, said: "Obama talks about us minorities as human beings, rather than a problem." Her friend, Carissa Sutton, 19, said: "I have a big problem with Mitt Romney telling women what their rights are when it comes to abortion."
Obama will on Saturday embark on his final marathon tour through Ohio, Wisconsin, Iowa and Virginia, before heading to Colorado, New Hampshire, Florida and Ohio again on Sunday. "We have made real progress," he told voters, pointing to encouraging figures on jobs. "But I come here today because we have got more work to do. Our fight goes on."