David Dimbleby hasn't just been nominated to preside over the much-anticipated head-to-head showdown between Major and Blair. He will also interview each of the party leaders in a series of Panorama specials. Then he will chair three souped-up editions of Question Time in which the would-be PMs will be cross-examined by members of the public. Then, just to make doubly sure that Dimbleby gets more TV exposure in this campaign than all the party leaders put together, he will also anchor the Beeb's election- night coverage.
ITV is also hoping to make broadcasting history, by screening the first presidential-style debate in the UK. And it, too, is putting its faith in a Dimbleby, namely Jonathan Dimbleby, who has also been lined up to present its election-night programme.
Why do the Dimblebys dominate political coverage to this degree? Forget scraps over the single currency, quarrels about constitutional change, tittle-tattle about tax cuts and tax rises, these are the questions the nation should be confronting in the next six weeks ...
Jonathan Dimbleby's pre-eminence on ITV is easy to explain - he is first in a field of one. The paucity of top-notch political presenters on the main commercial channel has come about because its ratings-obsessed schedulers have shoved political programmes into the margins. One of the few scraps thrown to political junkies is Jonathan Dimbleby's audience participation show on Sunday afternoons.
Politicians do still pop up frequently on News at Ten, but ITN has never really replaced Sir Alastair Burnet, the man it used to lend to the network for big national events. (Trevor McDonald is great at reading an autocue, but everyone accepts that he cannot interview for toffee).
Jonathan Dimbleby is still relatively new at the interviewing game, and is a lot more nervy - both on camera and off - than his big brother. But no one can fault his effort. "He works like buggery," says a former colleague from On the Record.
The decision to have David Dimbleby presiding over election-night coverage is also easy to explain. When it comes to anchoring big sombre national events, BBC mandarins simply can't see past him. Everyone who has worked with him testifies to his masterful ability to create an on-camera appearance of order out of behind-the-scenes chaos.
The Beeb might boast about having a whole roster of top-notch political presenters, but when their reputation for professionalism and political impartiality is really on the line there is no one they can rely upon as much as David Dimbleby, whose intellectual agility and cerebral stamina leave his colleagues gawping in admiration.
Clearly it is he who has inherited his father's mantle as Voice of the British People on Momentous Occasions. Richard Dimbleby, until his death from cancer in 1965, was probably the defining figure of post-war broadcasting, playing a central role in all the big state occasions from the Coronation to Churchill's funeral.
Belief in the monarchy and, indeed, most other institutions of the state has declined considerably in recent years, but when subjects of the realm gather round the Cenotaph in Whitehall or troop to the polling booths to decide who should represent them at Westminster, they expect David Dimbleby to be chronicling their actions.
"He's unique," says Tony Hall, the BBC's head of news and current affairs. "As well as being totally fair, I've never seen anyone handle complex and tense studio situations as brilliantly as he does. He's utterly unflappable.
"People can push any number of pieces of paper at him, issue any number of commands and directions into his earphone, and he always gives the impression to viewers that everything is under control and, what's more, he's thoroughly enjoying being at the centre of events. He's the great conductor who generates confidence among his colleagues and everyone participating in the programme."
Yet, for all his effortless supremacy, David Dimbleby was far from happy when Jonathan was hired by the BBC a few years back. According to some insiders, he even lobbied to have his appointment revoked. But his bosses overrode his objections, telling him that they believed an organisation with tens of thousands of people on its payroll was big enough for both of them.
They were wrong. Jonathan Dimbleby jumped back into the commercial sector when the first big offer came along.
Since then he has done his level best to corner the public limelight. In 1994, he authored a major documentary and a book about the Prince of Wales, in which he asked the heir to the throne if he had been unfaithful to his wife (a question posed with the prior agreement of the Prince, of course).
Jonathan Dimbleby has also ingratiated himself with Chris Patten, the last governor of Hong Kong, whom he will profile in a documentary series later this year.
Many in the broadcasting business wonder why he didn't stick with documentaries. "I'm no psychologist, but there surely is something peculiar about pitching yourself into direct competition with your elder and more successful brother," says one former colleague.
Others aren't so puzzled, seeing it as a classic case of sibling rivalry. Jonathan, as they see it, is the younger brother who tries harder because he has to.
But David Dimbleby arguably doesn't have the edge in every sphere of coverage. When drama rather than authority is what producers - and viewers - are seeking, he may not be the best bet. Indeed, his critics - and he does have some - believe that he can be pompous and dull. In the words of particularly harsh critic: "He's the quintessential fat-bottomed Englishman full of his own importance."
If the live debates come off, isn't there a strong case for BBC bosses living a little more dangerously and opting for a moderator with a little more mischief and irreverence in his make-up?
Sun readers certainly seem to think so. Last week, a reader poll conducted by Britain's best-selling daily found that Jeremy Paxman was the punters' favourite to host the live clash: 28 per cent plumped for the Newsnight presenter and 18 per cent for David Frost. David Dimbleby came a poor fifth, behind John Humphrys and even Mrs Merton, with just 12 per cent support.
The BBC's current affairs chiefs cannot be expected to take their cue from straw polls in the Sun. But this little survey seems to confirm the consensus view among the chattering classes that Dimbleby was a bland choice for host of Question Time.
Isn't the BBC in danger of overdoing the Dimbleby factor in its coverage of this marathon campaign? Senior figures in its news and current affairs department fear that it is, but none is prepared to go on the record.
Probably wise, for their supremo, Tony Hall, will hear no criticism of David Dimbleby. "I felt David was under-used in the past, which is the main reason why I wanted him to do Question Time," he says.
Hall also counters suggestions that Dimbleby is an establishment figure who lacks the common touch, pointing out that he was the first host of Question Time to come out from behind the desk and wander among the audience.
(It was, apparently, Paxman's failure to engage with the great unwashed that let him down in the pilot edition of Question Time over which he presided.)
Now, if Paxo aspires to put himself on a par with Dimbleby, he may have to do what Jonathan Dimbleby did a few years back and defect to ITV. Until then, British viewers and voters will just have to make do with the Dimbleby duopoly.