Early this week, I listened to the Big Three of the National Alliance for Change - Mrs Charity Ngilu, Mr Michael Wamalwa and Mr Mwai Kibaki - hold forth on why they should or should not name the single presidential candidate.

And then I remembered Mr Paul Muite's prognosis of a few weeks ago when he ruffled feathers by insisting the three would never agree on a joint candidate.

Well, I wouldn't go that far myself, considering that Mr Muite, who has taken to jumping from one sinking boat to another, was merely waging war on behalf of his new party, Ford People. But he had a point.

Mr Wamalwa and Mrs Ngilu want the joint candidate named now, without quite saying why, while Mr Kibaki does not think it is a good idea, though he too fails to give convincing reasons for his stand. 

But to me, a definite outcome is inevitable. The moment the joint candidate is named will be the beginning of the end for the joint initiative. And this for reasons that can be summed up in a word: Tribalism.

The mere fact that our politics is dominated by ethnic considerations above all else means that it will become quite difficult for the political leaders, however willing to accommodate one another they may be, to persuade their tribesmen and women to vote for the joint candidate.

As I said earlier, I don't have any idea why Mrs Ngilu and Mr Wamalwa should consider the timing propitious, but if their view prevails, it will be a major, maybe fatal, mistake.

On the other hand, Mr Kibaki's stand makes sense, even if he does try to convince Kenyans that his sole aim is to see democracy at work. Mr Kibaki has worked with President Moi as his Vice-President. He has been in Kanu since it was founded and knows its ways inside out. And he stands the best chance of being named the joint contender, for the Democratic Party is the only one in the NAC with a substantial following. Why then would he be so reluctant to get this whole business over with?

Precisely because he knows how President Moi and the ruling party work, Mr Kibaki is being very cautious and prudent.

He knows that if the contestant is named now, the ruling party will concentrate all its formidable missiles on the sole candidate and make it impossible for him or her to operate. The Opposition campaign team will immediately be infiltrated by intelligence agents and strategists, and its every move reported and used to scuttle the Alliance's strategies. It will be so distracted that instead of building a countrywide campaign network to counter Kanu's, it will waste precious time reacting to Kanu's moves and accusations.

On top of that, the more time the sole candidate has on his or her own, the more wrangles will erupt between the leaders of that loose coalition.

But the greatest danger is that the loose tribal "solidarity" represented by the Alliance will start tearing at the seams almost immediately, and in the end, it will not be possible to turn the Alliance into a mass movement capable of dislodging Kanu.

Why so pessimistic? Because ours is a tribal society. Let us face it. Suppose Mrs Ngilu was named the sole candidate; would the Luhya really vote for her? Wouldn't many conclude that Mr Wamalwa got a raw deal and vote for anyone but Mrs Ngilu? Would you really believe that a rural Kikuyu will vote for Mr Wamalwa just because Mr Kibaki tells him to? And if Mr Kibaki is named, does anyone expect that more Kambas and more Luhya will vote for him than did in the last election? I doubt it.

It could happen, yes, but only if the quintessential tribesman is not given time to reflect on the choices he has. In other words, the only way it can work is if the voter is ambushed at the last minute by the novelty of an experiment gone right.

But the majority, given time to remember that the Kikuyu ate during Kenyatta's time and it is the turn of the Luhya, or the Kamba, to eat, will definitely not vote for Mr Kibaki. On the other hand, if Mrs Ngilu is chosen, Kikuyus, who are reputed to be both tribal and gender chauvinists, will suddenly remember that Mrs Ngilu is, after all, a woman, and they have never been ruled by a woman since they overthrew Wangu wa Makeri.

And so on and so forth. And Kanu, which is a past master at exploiting the tribal sentiments in all of us, will have a field day. Don't Mrs Ngilu and Mr Wamalwa realise that to agitate for an early identification of the presidential candidate is to hand over all the ammunition to Kanu? Can't they use this as their secret weapon? After all, Kanu is not likely to name its presidential candidate any time soon, whatever the noise its functionaries are now making.