The tight camera shots as Barack Obama and John McCain duelled in the third and final televised presidential debate concealed the fact that there were many people present in spirit, including that Banquo's Ghost of this election: Joe the Plumber. It is certain Joe is being tracked down in Ohio for his opinion on who won.

Chances are it was not McCain, even though he turned in his best-yet debate performance, but not to the level he needed to reverse the reported major advantage Obama currently has in the polls. The thrusts that McCain needed to hit home against Obama - about Bill Ayers and ACORN - instead were easily deflected.

The characters who peopled the debate were the American middle-class taxpayer, who even though McCain invoked the American Dream may now be said to be living the American Nightmare; president Bush; Ayers, of course, and the respective running mates, Joe Biden and Sarah Palin.

After many weeks, McCain finally had a good line in response to Obama's consistent attempts to use Bush's two terms as concrete socks for McCain. As Obama once again claimed that a McCain presidency would be a continuation of the Bush years, McCain came back with: "Senator Obama, I am not president Bush. If you want to run against president Bush, you should have done so four years ago".

It was with the predictable opening question about the trauma hitting the US economy that Joe the Plumber made his appearance.

Joe, McCain said, had been in conversation in Ohio with Obama. Joe had concluded that under an Obama presidency, he would pay higher taxes.

Obama, seeking to rebut what has become a familiar allegation by the McCain camp in all the debates, said that both he and McCain wanted to cut taxes: "the difference is, who for". To camera, Obama repeated the now-familiar: "If you make less than $250 000 a year, you will pay less tax". Joe the Plumber would benefit, he said. So would others, and in any case, 98 per cent of small businesses in the US made less than $250 000.

McCain challenged Obama: "we need to spread wealth around," he said, and it was Joe who should be allowed to do so. "Why would you want to increase anyone's taxes right now, especially in tough times?"

It sounded good, but Obama was ready - not surprisingly considering how often the charge has been repeated (it is perhaps inevitable, this late and long into the presidential contest when so many things have been repeated so many times, that rivals sound like an old married couple revisiting long-unresolved household squabbles). "I want to cut taxes for 95 per cent of Americans," Obama said. And yes, this would include Joe the Plumber. Nobody likes taxes, Obama said, but some could better afford to pay them.

On the mounting deficit and the question of trimming back spending, McCain - so often accused by Obama and his camp of offering an across-the-board spending freeze that was tantamount to a hatchet when a scalpel was needed - was ready to respond that his use of a hatchet would be followed by the use of a scalpel. ( I was dearly hoping by this stage that one or the other candidate would come up with a wrench analogy, to keep Joe in the picture, but sadly neither of them thought of it.)

Then came the question that so many had been waiting for - no doubt including Obama, and certainly everyone in the Republican camp that had been urging McCain to take the gloves off; the one about the nastiness on both sides, the accusations of lying, and in a paraphrase of Obama, that these allegations, in no debate so far, had been made face to face. In other words, it was the Bill Ayers question; the racism question.

"This has been a tough campaign," McCain said. He regretted some of the negative aspects of both campaigns (points for the finesse in saying that); and then he went face-to-face, challenging Obama about things said in his camp that Obama had not repudiated, saying that Obama had spent more money on negative advertising "than any campaign in history" (that would have got the fact-checkers busy immediately) and accusing Obama of not keeping his word on promises including that the two of them would have many "town hall meeting" debates.

Obama: "We expect presidential campaigns to be tough…100 per cent of your ads, John, have been negative". But, Obama went on, Americans were "less interested in our hurt feelings" than in their own economic plight. Town hall meetings would not help when people wanted to talk about the economic crisis.

McCain: "You're running ads how I oppose federal funding for stem cell research. I don't." He added that Obama had misrepresented his position on migration.

Obama came back with the Palin and McCain meetings where people in the crowd had referred to him as a "terrorist" and some had shouted "kill him". The American people were becoming cynical about politics when all they saw was tit-for-tat in campaigning.

McCain's manouevre was to stand by those who attended his rallies as dedicated patriotic men and women, while saying that he had repudiated such statements. He added an objection to "some of the things yelled at your rallies," he told Obama.

And then it was Ayers and ACORN. Inevitably, Obama was well prepared, especially because McCain first had telegraphed that Ayers would come up in the second debate, which he did not, and then had said Ayers would be there in the third.

Ayers, Obama said, had been involved in "despicable" things - "40 years ago, when I was eight years old". Yes, he said, the two of them had been together on a school board - one funded by one of the Ronald Reagan funds, and whose members included leaders from the University of Illinois and the Chicago Tribune. "Mr Ayers is not involved in this campaign, will not be, and will not advise me in the White House." ACORN, Obama said, had "nothing to do with us". The people he associated with were Republicans and Democrats and with them, his ideas had been shaped.

McCain: "You sent $230 000 to ACORN". Obama: "Not true". (Another one that would have had the fact-checkers scrambling.)

Asked to list the respective advantages of their running mates, Biden and Palin, Obama and McCain came up with interesting lists.

Biden was one of the finest public servants, with strong foreign policy credentials, who had never forgotten where he came from, a fighter for the "little guy" and would make an outstanding president, Obama said.

Palin was a role model for women (I confess that I did think of Tina Fey in particular at this point), had given money back to taxpayers, cut back government, was a reformer through-and-through and had a special understanding of special needs families. "I am proud of her," McCain said.

The follow-jabs on both sides were ineffectual. Obama paid tribute to Palin being "commendable" about special needs families but got in a stab that just such needs would not be served by McCain's proposed across-the-board spending freeze. McCain called into question those very "foreign policy credentials" of Biden, saying that Biden had been wrong on issues including by voting against the first Gulf war.

The question on screening candidate supreme court judges for their views on Roe v Wade opened an interesting phase of the debate. The technicalities aside, Obama probably did the best in the women voters' constituency on the issue (but traditionally termination of pregnancy is an issue that favours Democrats) by emphasising a woman's right to choose, and shooting back at McCain's assertion about leaving the issue to individual states by saying that on this and other issues, states could not be allowed to pare back constitutional rights.

The closing states were, surprisingly, rather dull, coming across as precisely what they were, a checklist of talking points rather than anything that will go down in the history of inspirational quotable quotes - even the Obama rhetoric for which McCain less than subtly mocks his rival appear to subside into paint-by-numbers stuff.

McCain emphasised his record of reform, the need for a new direction because of the past eight years (presumably, he is not running against Bush either, but McCain does like to emphasise to his advantage where he has dissented from the Republican establishment). "I have been a careful steward of your tax dollars," McCain said, and noted the "long line of McCains" who had served America. "I've been proud to serve you and I hope you give me the opportunity to serve again".

Obama opened by repeating for the third time that America faced "the worst economic crisis since the Great Depression". "We need fundamental change," he said, and one heard an echo of the message with which his campaign started. "We need to invest in the American people again," Obama said, through tax cuts, education and growing the middle class. It would require "all of us, Democrats and Republicans" to come together.

The final question is whether anything was said that made Joe the Plumber change his mind. It is quite certain we shall find out, if not through an enterprising reporter or campaign trooper tracking him down, but at least on November 4 when Joe and millions of others pronounce their verdict.