The 'Battle of the two Davids' is really a first for Conservative Party members. Yes, they've been asked to choose before: in 2001, between IDS and Ken. But then euro scepticism dictated the outcome – and sealed the fate of both.
Today, it's different. Whether the Conservative Party is able to win the next election – yes, to win it outright, not just eliminate Labour's majority – may well depend on who is chosen. This is what makes this leadership contest supremely important. The choice is not one to be made casually. I think party members are aware of the dangers of sleepwalking to a decision.
In running a business, I've always found it far more productive to concentrate on the strengths of my colleagues, not on their weaknesses. And that's how Conservative Party members should approach their task in the coming weeks.
This contest is not a sprint. The whole campaign out on the hustings is designed to give members the chance to see, over a longer period, how effectively David Cameron and David Davis withstand sustained interrogation. Above all, they will see how clearly and compellingly they each spell out the direction they want the party – and if they are successful, the country – to take.
Most party members were not at the party conference. So the television debates – on BBC, ITV and Sky – between the two candidates should be compulsory viewing.
We will see Cameron as 'The Celebrity'. He is a bright and attractive face with a glitzy past and a glitzy present. This is why he was able to dress up in his cycling kit without the derision William Hague got for wearing a baseball cap. Within the space of a fortnight, he achieved instant popularity.
What a relief it must be for Conservatives, who for so long have felt themselves objects of ridicule or contempt, to be interesting and popular. In fact, many will find the experience positively intoxicating.
Learning from Blair
David Cameron and his advisers have meticulously learned lessons from Tony Blair – how to present a new face; how to say simply things that attract people rather than things that put them off; and how to get much of the media on side. All this matters. You have to be popular to win votes. But the Conservative membership must be careful to avoid trying to refight the past three elections and instead prepare for the next, particularly while Blair is becoming less and less popular.
When the next general election comes, in 2009 or 2010, Blair will probably be history. Whichever David wins will be fighting Gordon Brown, not Blair. Brown will certainly not be trying to 'out-Blair' Blair. The challenge then will be to 'out-Brown' Brown.
Over the past few years, the Conservative opposition has found it very difficult to land a blow on Brown. The economy just wasn't an issue in either the 2001 or the 2005 election. I suspect things will be very different at the next one. Brown could, for the first time, be on the defensive. But he will still be very formidable. So the new Conservative leader will need all his skills – parliamentary, rhetorical and tactical – to cause political injury.
Which brings us to Davis, 'The Politician'. The ordinary chap from an ordinary background, despite a stint in the SAS.
Davis has two ministerial scalps to his credit: Beverley Hughes and the far juicier one of David Blunkett.
Each one tried to slither away. They couldn't. Davis won each one by sheer tenacity and skilful tactics, not least with the media.
By reinforcing the impression of sleaze, each of these forced resignations did the Government great harm.
This talent is not to be underestimated. Elections tend to be lost by unpopular governments rather than won by popular oppositions. In 1970, the election was lost by Harold Wilson rather than won by Ted Heath. The 1979 election was lost by Jim Callaghan. And in 1997, John Major was doomed after the ERM fiasco.
So the skills of effective opposition – to exploit mishaps and misbehaviour – are vital to bringing about the decline and fall of a government. Being tough enough to take apparently unfashionable positions is an important opposition characteristic. Over time, I have learned two rules about winning and losing elections. An opposition party, however popular, will not by itself bring down a government. And an unpopular government will lose only if the opposition party looks serious. Does it have a clear sense of direction? Is the opposition leader a credible prime minister? If it does, and if he (or she) is, then the electors will be prepared to kick out a government in which they have lost confidence.
So, of course, in addition to having the skills of opposition, the Conservative Party must look like a government in waiting – ready to be the recipient of the 'time for a change' mood.
Both leadership candidates are branding themselves, in their own way, as 'modern' Conservatives. But both will, over the course of a parliament, have to spell out what this means.
Blair modernised the Labour Party by repealing Clause 4 and introducing the word 'New'. The Clause 4 abolition was a brilliant shorthand way of saying to the country: 'We're not the party
we were. We've changed.' What's more, in forcing these reforms through, Blair also showed that he was made of steel – vital to differentiate himself from his weak predecessors, who had been accused of being in thrall to the trade unions.
The Tories do not have an equivalent Clause 4 and they should not try and invent one. So whoever becomes leader will have to answer the fundamental questions raised by the idea of modern Conservativism.
What will a modern Conservative Party stand for? What will it actually do if Cameron or Davis becomes leader? What direction will the party take on the issues of the day? And what will those issues be at the time of the next election? How will the new leader take on Brown?
Indeed, it's possible that the forthcoming TV debates between the two Davids could set a trend. They may well create a demand for television debates at the next election between the two party leaders. And then the question would be: how would each of the Davids fare in those television debates against (probably) Brown?
These are the questions that Conservative Party members should ask themselves over the coming weeks.
Tim Bell has advised the last five leaders of the Conservative Party. He is not advising either of the current candidates.