With so much attention lavished on the debates between Messrs Brown, Cameron and Clegg, it is surprising that so few commentators have looked back to the great prime ministerial debates of the past. Ever since that groundbreaking televised debate between Harold Wilson, Jo Grimond and Sir Alec Douglas-Home in October 1964, mastery of the medium has played a central role in every general election campaign. Without them, Edward Heath could have been PM - and we might have been spared the government of William Hague.

That first debate, of course, seems impossibly antiquated today, what with Sir Alec's strangulated accent and Richard Dimbleby's insistence on calling each of the participants "sir". But it marked a turning point in British politics. Presentation now mattered as much as policies, and the Tory leader's skeletal visage was enough to swing millions of voters to Labour.

The man who benefited most from the format was Wilson: after landslides victories in 1964 and 1966, he annihilated poor Ted Heath in 1970. The Tory sailing enthusiast was disadvantaged by his lurid orange make-up and bizarre use of nautical metaphors. It is a safe bet that no aspiring prime minister will ever again begin his opening statement with: "Ahoy there, shipmates."

But the next Tory leader, Willie Whitelaw, was even worse; his performance in the 1974 debates, especially in contrast with the witty Jeremy Thorpe, was perhaps the biggest factor in the Tories' fourth consecutive defeat.

Things were a little better for the Conservatives the next time around, though Jim Callaghan's avuncular put-downs to Margaret Thatcher - for example, his notorious response to a list of strike statistics: "There you go again, little lady" - make painful viewing today. But Labour's luck ran out with Callaghan's successor. Michael Foot's insistence on behaving in the 1983 debates as though he was at some great meeting in Trafalgar Square was all too much for most viewers, and his frequent references to Swift and Hazlitt went right over their heads.

For the past decade or so, there has been much talk of scrapping the debates on the grounds that they are mere beauty contests. It is doubtful whether Tony Blair would have beaten Douglas Hurd in 1997 without one (there again, make-up was a critical factor), but he was hoist by his own petard four years later, when William Hague's stand-up routine had the audience in stitches and millions rushed to the Tory banners. This year's debates were downright boring in comparison. Next time, let's do without them altogether.