As the Obama-Romney debates showed, facing off on TV with your opponent is an important stepping stone to the White House.

If Mitt Romney does end up becoming America's 45th president, he would look back rather fondly on his first television debate with Barack Obama on October 3. As a reticent and rather defensive Obama stumbled his way through his responses on national television that night in Denver, Romney pulled ahead in surveys for the first time in a race most presumed the Republican had already lost. Obama surged back in the other debates, but Romney's now a clear contender for the presidency come Election Day;and offers a good example of how crucial the tradition of one-on-one debating on the small screen is to American elections.

In fact televised debates between presidential candidates debuted with a bang in 1960. Despite the initial scepticism that abounded in a presciently worried print media - with The Wall Street Journal cautioning, for instance, that such TV debates would be "rigged more for entertainment than for enlightenment, " - that first face-off between John F Kennedy and Richard Nixon, the serving Republican vice-president, proved instrumental in swinging a very close election the youthful Kennedy's way. It also launched US electoral politics into the TV age.

At debate's beginning, Kennedy was largely unknown across the US, except for his being a Catholic in a largely Protestant nation;but by its end that September night, as one observer laconically noted, 'he emerged a star. ' While weighty arguments were traded on both sides, Nixon, coming off a recent hospitalisation, appeared so pallid, sweaty and ill-prepared that one pundit later tuttutted that he looked "like death warmed over. " Kennedy was a study in contrast. Handsome, tanned, clearly next-gen, confident and well-prepared, he went on to prove what being appropriately telegenic (wags would even dub his primary campaign appeal as 'Sex for President, 1960') could do in a new age in which 88 per cent of Americans were already hooked to TV programming.

Nixon would turn in better performances in the next three debates but the damage had already been done - both for 1960 and for the next 16 years, as spooked candidates shied away from taking part in these televised sessions until 1976. Lyndon B Johnson, who succeeded Kennedy and successfully fought the 1964 polls, refused to do any, despite his markedly outspoken Texan ways;as did his Oval Office successor in 1968, who would also go on to win a landslide second term in 1972 without using them, Richard Nixon.

The debates only resumed in 1976, when President Gerald Ford agreed to match wits with his peanut-farmer Democratic challenger, Jimmy Carter. Ford faltered in the debates, dropped bloopers (sample: "Poland is no longer under communist domination" ) and found himself shoved aside in the '76 election.

The next set in 1980 would prove instrumental in bringing America's 'Great Communicator' to political centrestage. Ronald Reagan, a former Hollywood actor and successful California politician, had re-energised the Republican Party and won the nomination, but was still not a firm political proposition to the rest of the nation. His debates with the embattled Jimmy Carter, watched by a massive TV audience of 81 million, are seen as being a major turning point for his bid. Reagan appeared cool, witty and folksy in front of the cameras, even as an overwrought Carter failed to impress audiences in the wake of an economic crisis and other national security woes, including a grave hostage crisis in Teheran.

Body language can also be a problem for some. In 1992, the incumbent, George H W Bush, checked his watch for the time during one debate. Opponents seized on that to portray the patrician Bush Sr as too haughty, too busy and mostly out of touch with real issues. Bill Clinton, a master communicator, would corner the Oval Office that year, and would also use his 1996 reelection debates - when Monica Lewinsky was but merely a starry-eyed White House intern - to drum home the fact that he was a successful president and also a whole generation younger than his '96 opponent, Bob Dole.

In 2000, Al Gore probably fancied his chances of using the debates to show America just why he needed to move to the White House from his vice presidential digs, especially considering his opponent's more simpleminded reputation. But despite George W Bush's infamously gaffe-prone campaign, Gore would go on to lose the narrowest and most controversial election in US history in over a hundred years to Bush. It had a fair bit to do with what happened in that year's TV debates. To many Americans Gore appeared 'wooden', 'boring' and pedantic, while his somewhat condescending sighs and smiles when Bush was answering questions had significant negative impact, as did his 'invasion of Bush's space' when he got unnaturally close to interrupt him in one debate.

However, like with much in American entertainment there's also the flip side to consider: these debates sometimes make no real difference to the outcome. Dubya figured that one out for 2004. John Kerry is generally held to have won every TV debate against Bush that year but still ended up losing the election by a significant margin. Largely why for some political pundits at least, the debate's still on.