The small shindig to celebrate the opening of an "Obama for President" office in a mall near the centre of Strongsville, a tidy suburb of Cleveland, Ohio, is a relaxed affair. Volunteers swap campaign gossip and pick at devilled eggs and cold pizza. Topic A: the drubbing, as they saw it, of Mitt Romney at the debate the night before. Yet this evening's social is merely a pause in a ferocious war, the outcome of which is still in the balance. True, the Barack comeback at the Hofstra University debate on Tuesday may have an impact on the race, yet the fate of his re-election campaign will also turn on the efforts of these 20-odd volunteers and others like them across Ohio.
"This is push time," Carolyn Reed, 63, recently retired from her job as a parole officer supervisor in Cuyahoga County, said in a tone of urgency and a little glee. Wearing a "Made in the USA" button with an image of Mr Obama's sometimes contested birth certificate, she adds quickly: "And we really have to push a lot!"
Of the 10 or so swing states that will decide this election, none matters more than this one. It is why Mr Obama flew to Ohio after Hofstra on Wednesday, making his 16th visit to the Buckeye State as President, and why Mr Romney and his running-mate Paul Ryan have recently made Ohio a virtual home away from home.
The reasons are stark. As Mr Obama has seen his edge in the polls evaporate since the first debate in Denver, Ohio has become his final firewall against defeat. For Mr Romney, the state is a must-win, pure and simple, not just because it will deliver a large trove of 18 electoral college votes on 6 November – it takes 270 of those votes to win the White House – but also because of the evidence of history. No Republican has become President without winning Ohio. The last Democrat to take the White House without Ohio was John F Kennedy in 1960. Add to that the fact that Ohio is in many ways a microcosm of America. It has multiple large urban areas, including Cleveland, that continue to favour Democrats. Many also have large black constituencies, although missing from Ohio is a significant Latino presence. The Republicans have redoubts too, in the rural Appalachian country in the state's east and south, and in the recently-grown suburbs like Strongsville.
"Taken together, it is a fairly close mirror of the country, demographically, economically, socially," agrees Gene Beaupre, a professor of political science at Xavier University in Cincinnati, on the state's western edge. "That's one reason it has accumulated a history of being important." There are large universities, coal-mining regions, farming communities and industrial areas that suffered severely from the loss of manufacturing.
Both parties know that winning or losing will depend on their ground games in the swing states. That means having the volunteers like Ms Reed and giving them the tools and data to knock on the right doors and canvass the right homes. The evidence is that Team Obama is better at this – there are now nearly 100 field offices working the grassroots for Mr Obama in Ohio, for instance, versus fewer than 40 for the Republican ticket.
Don't worry so much at this stage about changing people's minds or even finding those elusive undecided voters, says Saadi Alikhan, another enthusiastic member of the new Strongsville outpost, set up in a vacant shop front next door to a mattress showroom. One of its bare walls is plastered with round "Obama-Biden" stickers placed to spell out the President's last name. A back-room is equipped with three computers paid for by campaign HQ in Chicago. Everyone who has turned up is asked to fill out a small shift-sheet setting out the days and times they will commit to working the small bank of phones here, or tramping the streets of Strongville.
"There is no point in riling up the Republicans any more," says Mr Alikhan, 68, a retired engineer for Ford, which has three plants in the area. "Most people have settled on their candidates. This is about getting our people enthused and making sure they actually vote."
The campaigns themselves are doing their part, of course, most of all by showing up as often as possible. They are also bombarding Ohio with celebrity surrogates. The buzz here yesterday was an appearance at a community college in Parma, a few miles from Strongsville, by the former president, Bill Clinton, and Bruce Springsteen, music icon and working-class hero. Among those who were rocking to the beat yesterday was a thrilled Ms Reed.
Other, more political, heavy weapons are being deployed. When Mr Ryan visited Baldwin Wallace University in Berea, next to Cleveland airport, on Wednesday, he brought along the former Secretary of State, Condoleezza Rice. It was her first outing aside from her convention speech for the Romney-Ryan ticket. This weekend will see campaign appearances on behalf of Mr Obama by the Chicago mayor Rahm Emanuel, a former White House chief-of-staff.
While ahead of Denver, Mr Obama seemed almost to have Ohio in the bag, today it looks entirely more dicey. Two polls released last night, one by Rasmussen and another by SurveyUSA, gave the President leads of only one and three points respectively, by no means safe margins.
And each side has been talking up their chances of taking the state, notably to reporters crammed into the "spin room" at Hofstra straight after Tuesday's debate.
David Plouffe, the top Obama strategist, raised eyebrows when he named Ohio, Nevada, Iowa and New Hampshire as the four bastions of support that would ensure his candidate's re-election. (The comment elicited headlines that the Obama campaign was giving up on Virginia and Florida, which it hastily denied.) If they are indeed confident of Ohio, one reason may be the trends in what has already been heavy voting in the state. As of the end of last week, one in five Ohioans had voted and Obama was winning those early voters by a 63-37 per cent margin.
"I really don't see a path for Romney without Ohio," Mr Plouffe said. "And we feel very good about where we are in Ohio with voter contacts, messaging, and early voting. Our early voting is ahead of where we were in 2008." Not so fast say the other side. "God bless them in the Obama campaign," countered Sean Spicer of the Republican National Committee.
"We are gaining in Ohio, and they can say all they want about early vote. We are way, way ahead in early voting in Ohio compared to 2008, and what matters are residual voters after the early vote. We believe we will have enough to win."
A few things may be giving Mr Obama some early steam, however, not least a recent pick-up in job creation in Ohio where the unemployment rate now runs below the national average. Meanwhile, it was no surprise that Mr Obama emphasised the steps he took early in his term to rescue General Motors from bankruptcy.
It is the bail-out – Mr Romney at the time wrote an article advocating letting the carmakers enter bankruptcy – that makes Josh Peters, 34, a business consultant in nearby Cuyahoga Falls, think he knows which way the state will fall. A swing voter himself – he has voted for both parties in the past – he is ready to give Mr Obama another shot. "He will win Ohio strongly," he predicts, citing Mr Romney's shifting positions. "If he [Romney] was how he was as Governor of Massachusetts I would vote for him, but he is not."
Also galvanised by the car industry debate are the unions that remain an important presence in Ohio despite efforts (eventually thwarted) by Republican Governor John Kasich to weaken them. Leaders of the AFL-CIO union confederation have plans to reach out to up to 2 million Ohio voters between now and 6 November.
Back at the Strongsville office, Mr Alikhan also singles out the rescue of the car industry as Mr Obama's trump card, noting the concentration of car plants around Cleveland. (His old company, Ford, never took the bail-out.) "In one fell swoop, he saved 800,000 jobs," he argued, many of them union jobs paying good money. And that is not to mention all the local suppliers to the car companies who also would have gone under if they had.
Among all Obama's Ohio volunteers, the folks chewing pizza here perhaps have the toughest assignment. As a whole Cuyahoga County remains heavily Democrat. But to win the state on election night, Mr Obama must not only win the county but win it by the widest margin possible to offset Republican wins elsewhere. That means going to full battle-stations in Strongsville precisely because it is heavily Republican.
That Mr Obama did altogether better at the second debate at Hofstra is certainly likely to help. If it prompts a new surge of enthusiasm it won't come a moment too soon, says Mr Alikhan. "I am worried, yes."
Over recent days and weeks, it has been a challenge to get the Democrats here excited about Mr Obama again. Mr Alikhan says: "They had high expectations for Mr Obama and, in some ways, those expectations were dashed. Some of our people have been disenchanted."