Matthew Norman: Politics needs bringing to life. And this might just do the trick

Christmas has come early this year for Nick Clegg. If there was one thing the lad put at the top of the wish list he posted to Lapland, it was a live televised election debate.

Santa has delivered ahead of schedule for the Liberal Democrats' leader, and thrice what he asked for, and the gift of three live debates must make him the happiest boy in all the kingdom. Facing a desperate rearguard to cling on to Tory-threatened marginals in the South-east, London and the South-west, this is an escape route, a godsend and a Christmas miracle.

Of course, it's no gimme that Nick will win all or any of the debates. But he is a very impressive TV act who scores brilliantly with those little focus groups that Frank Luntz conducts now and then for Newsnight.

Besides, exposure is electoral elixir to the third party, and just by appearing with equal billing to his rivals he will reap a rich reward. He might think about smoking a few packs of untipped Players No 6 the night before to lower his voice a couple of octaves, because where the oxygen of publicity is one thing the helium of publicity is quite another. But barring some drastic calamity – a Tourette's-style blurting out of that myriad of ex-lovers' names, for instance, or injecting an eyeball with heroin – he is virtually guaranteed a sharp bounce in the polls.

For the other two leaders, predictions are more difficult. Both have agreed to debate from positions of weakness, because no politician would dream of doing so from one of strength. David Cameron, no mean TV turn himself, is more aware than ever that the deal remains unsealed with his lead definitely, if slowly, contracting. The conundrum for him is the one that affects football teams leading 1-0 midway through the second half. Do you try to kill the game by going for a second goal, or defend deep in the hope of hanging on to that slender lead? There are grave dangers either way.

For Gordon Brown, the danger is simpler. One could devote tens of thousands of words to analysing this, and perhaps one should. But space is short, so we'll boil it down to four. He's a telly catastrophe. Disturbingly unnatural and unnervingly weird, with the top lip of The Joker, eye bags the size of Caligula's imperial couch, waxen flesh the hue of unwashed grey flannel, and the rictus grin of a jackal in its death throes, he is by light years the least accomplished television act of the trio. His MPs' expenses tour de force should be made available to any outsourced Syrian torturer tired of strapping electrodes to genitals.

In the Downing Street bunker today, they must be making as many frantic calls to media trainers as to Hollywood make-up artists. They have a few months to make him look healthy, or at least not in the early stages of rigor mortis. Even if they beat the clock on that, there is his ill-concealed petulance to fret about. The faintest hint of a toddler tantrum like those that sent him storming out of conference studios in September, and the game will be up.

Now there are those in the punditry game who would regard the above as madly exaggerating the relevance of these debates. I've already read a couple of magisterial articles dismissing them as little more than another minor staging post on the road towards a presidential system, and concentrating more on the identities of the moderators (David Dimbleby – there's a shock – for the BBC; the studiedly inoffensive Alastair Stewart for ITV; and Adam Boulton, portly husband of Mr Tony Blair's great mate Anji Hunter, for Sky) than the implications for the candidates.

Perhaps these wise old Nestors are right that the debates will generate far more heat than light. Yet it seems to me that the emotional thermometer will play a major part in settling this election. US election debates matter not because they shine a halogen lamp on policy. Few viewers are so naive as to believe that what their wannabe leaders promise will be done. Infinitely more important in shaping the decision for the tens of millions who do not follow policy closely is the more nebulous matter of temperament, because that gives a guide to how well they will handle the unforeseen crises that tend to shape a presidency.

This is why last year's debate season was such a boon to Barack Obama. It wasn't what he and John McCain said that made the difference. After one debate, the consensus among network commentators (on CNN as well as Fox) was that McCain had landed the cleaner blows and won tidily on points. The opinion of the punters at home was that Obama smashed him to pieces. They saw the younger man as calmer, more at ease with himself and, paradoxically, more grown up. They couldn't avoid noticing that the older guy had a volcanic temper bubbling away and a creepily artificial smile (bring anyone to mind?).

Before the first debate, Obama was the likely winner. After the last, he was the prohibitive favourite. The impression many undecideds had formed that McCain was a histrionic hot head, from his suspension of the campaign to fly to Washington to address the banking crisis, had solidified. The gut instinct that Obama was cool in judgement as well as in busting moves on Ellen had hardened. The opinion polls barely oscillated again.

The situation here isn't directly comparable, because there was no incumbent over there while we've had a dozen years of Gordon running the country and four of David as PM in waiting. The dynamic of a three-way fight is also very different. With three man-to-man rivalries on display rather than one, the tactical nuances become more complex (Who do you attack? Do you tag team with one of the others and gang up on the third?), and the potential for landing haymakers reduced.

Even so, this is not a small moment in the history of British politics. The appetite for political confrontation is enormous, as the viewing figures for Nick Griffin's Question Time confirmed, and the feverish hype should ensure X Factor final-sized audiences.

That alone will not obliterate the apathy, unbroken by anything but expenses, that has enshrouded British politics for years, but it will certainly help. An election that already promised to be the most unpredictable and intriguing since 1992 suddenly becomes all the more fascinating and hard to call. Barely a day passes without someone clever taking to cyberspace to explain why a single percentage point either way could mean the difference between a majority and minority government. Can anyone believe that after four-and-a-half hours of live combat, two or three people out of a hundred won't change their minds?

We have needed this for ages. It would be lovely to sit here pontificating about the coarsening and trivialising of politics, and the sinister imperium of Cowellesque presentation over high-minded substance. But it's the telly that shapes the thinking of many more millions than are influenced by manifestos and weighty articles about policy. Anything that broadens the reach of political argument, however over-rehearsed and soundbitey, and injects the necrotic with adrenaline, must be a positive thing. These debates will prove a blessing, and not only for Nick Clegg.