The first presidential debate I witnessed was in Cleveland, Ohio, between President Jimmy Carter and Ronald Reagan in 1980, writes Conor O'Clery
Things were pretty even until the Republican challenger put down a too-clever Carter with the words: "There you go again." The remark helped Reagan win by a landslide.
Four years later, when well into his 70s, Reagan again threw his opponent, this time Walter Mondale, off balance by saying: "I will not make age an issue of this campaign. I am not going to exploit for political purposes my opponent's youth and inexperience." There was no comeback to that, as a losing Mondale later admitted. On both occasions expectations for Reagan to win the debate were low, and he benefited from that.
It was much the same when George W Bush faced Al Gore in 2000. The Democrat came across as overbearing when he stalked the supposedly lightweight Bush across the stage.
The first of three debates between President Bush and Senator John Kerry will take place on Thursday in Coral Gables, Florida. They could well decide the 2004 election, and both sides are trying to lower expectations.
Even a careless gesture - such as George H W Bush looking impatiently at his watch during a 1992 debate with Bill Clinton - can make a bad impression on a voter tuning into the race for the first time.
With the lead in the polls swinging back and forward between Kerry and Bush during the year, a surge among undecided voters at the right time could decide the outcome, especially with the race now tightening to a mere three-point lead for Bush, according to the latest Wall Street Journal-ABC poll.
I first saw John Kerry debate at a university in Columbia, South Carolina, in May 2003 when all nine Democratic candidates came together for the first time.
Looking back at what I wrote then, I can see that the seeds of Kerry's fumbled campaign had already been sown. The Massachusetts senator was scorned by his Democratic rivals as "Bush lite" for his support for the war in Iraq.
When Howard Dean accused him of not having the courage to oppose the war, Kerry said no one should lecture him - a much-decorated Vietnam veteran - on courage. And when someone put it to him that he lacked the common touch, Kerry replied with a laugh: "I think I'll just disappear and contemplate that by myself", but it was clear that he was not very lovable.
Right up to the Democratic convention in Boston, Kerry continued to portray himself as "Bush lite", muting his criticism of the war. He seemed to believe that his best chance of beating Bush was to go along with the patriotic flow, and to campaign on economic issues such as jobs, healthcare and social security.
In Boston he hammed up his war hero image, saluting and "reporting for duty" - and setting himself up for vicious attack ads by Vietnam veterans who never forgave his anti-war activities in the 1970s.
His numbers fell in August as Kerry hesitated to defend himself, while Bush steamed across the country, riling up patriotic rallies by talking tough on terrorism and mocking his opponent for his "flip-flops". The President portrays a core conviction that he has to "take the fight to the terrorists" in Iraq rather than have to face them at home. He has even reversed Kerry's lead among women by getting the support of "security moms" concerned about keeping America safe.
Kerry still did not reply in kind, believing that the high road would take him to the White House, but the idea that he flip-flopped became the touchstone by which everything he said was judged. He is now paying for the choices he made when positioning himself to beat Bush.
Kerry voted for the war in October 2002 to secure his national security credentials, then voted against Bush's bill of $87 billion when Howard Dean was surging on anti-war sentiment. He said iSeptember 2003 that it would be the worst thing to send more troops; then in April that more should be sent if needed. Last month he said that knowing what he knew now he would have still voted to give Bush congressional authority for war.
The Bush campaign, meanwhile, had almost succeeded in making the election a referendum on the challenger.
The bounce that Bush got from his convention came as a shock to Kerry, and last week he abruptly changed course.
He began to carve up the President on Iraq, which had dropped from the headlines in August, but was again dominating the news as cities fell to the insurgents.
He said for the first time he would not have gone to war, despite his vote in Congress, and accused the President of creating a crisis of historic proportions through incompetence. He has baited Bush on television at every opportunity on the war, believing it now to be an issue that could go either way.
Only four in 10 voters now think toppling Saddam was worth it, and an astonishing majority (47-41 per cent) actually think the war will be lost, according to the Wall Street Journal-ABC poll.
It is a high-risk strategy, but ceding so major an issue as the war to Bush would now mean defeat. To regain ground, the Democrat has to make the election a referendum on a commander-in-chief who flip-flopped on his reasons for war and then blew it through incompetence.
Kerry has only 38 days left to erase his image as someone who is too indecisive to be commander-in-chief.
He is doing it by attacking Bush every day on every issue, from the war to the job losses during his term. It may be too late, but the presidential debates will give Kerry a last opportunity to define himself.
The Democrat would do well to look back to that Reagan-Carter debate for a handy line to use against the incumbent. "Is there more or less unemployment than there was four years ago?" asked Regan. "Is America more or less respected?"