BALDRICK: I’d love to be a flier. Up there where the air is clear.

BLACKADDER: The chances of the air being clear anywhere near you, Baldrick, are zero.

“Clear air” is the new black in politics. “Narrative” is so August 2008. I can’t help but think of Baldrick whenever someone suggests that Brendan Nelson can, now that Peter Costello has kinda sorta vacated the field, get some “clear air” in which to perform. Nelson certainly doesn’t — as far as I can tell from press conferences — have Baldrick’s foul odour, but he has the same chances of finding clear air. The only place the bloke is going to find clear air now is in a wind tunnel.

Not that he never had it. He had plenty of clear air earlier this year. It didn’t do him any good. It merely made sure that everyone was watching when he stuffed up, which he proceeded to do on a number of occasions.

I keep doing a reality check on all this. Surely it’s merely because, being in the Press Gallery, I just want to see a leadership challenge. Surely these are experienced political operators, and what would I know being on the sidelines. But I can’t work out how it can be possibly be politically smart to leave Nelson there, even if Malcolm Turnbull would prefer to wait until even party conservatives are calling him and telling him to finish it off.

Andrew Robb’s argument that the best thing for the party is for everyone to knuckle down and get on with their jobs is true enough, but it’s not going to happen. Not with Costello still on the backbench, not with everyone waiting for Nelson’s next gaffe, not with the clock ticking, every second and every opinion poll taking Nelson closer to the end.

And not with Tony Abbott and other, more anonymous, Liberals opening their yaps every day to offer their own self-interested take on events.

The only people knuckling down and getting on with the job will be Kevin Rudd and his ministers, confident they can operate without serious pressure from the other side. And Rudd only looks vulnerable when he’s under pressure.

Costello has denied that the incessant speculation of recent months has damaged his party – and that in any event, nothing he could have said would’ve ended it. If he means that, he is being staggeringly obtuse. More likely, this whole saga has been quite deliberate on his part.

This entire act, from the time he declared he was writing a book, appears to have been an extended act of revenge on his own party, on the people who refused to accept him, on those rejected him even when they knew they were stuffed under Howard’s leadership. And as revenge it is quite brilliant. The fact that he has barely had to lift a finger — that indeed it depended on his silence and inaction – made it all the better. The damage on the party was entirely self-inflicted; Costello merely declined to do anything to stop it. How perfect is that?

That’s why he continues to stay in Parliament, declining to declare his political career over – he knows that his merely presence will continue to drive his colleagues mad with frustration and speculation. And if it helps to stymie Malcolm Turnbull for even a second, that’s icing on the cake.

His party can end all this whenever it likes, by installing Turnbull and a decent deputy. Preferably the only person throughout this whole saga who has kept talking sense, Andrew Robb. Laurie Oakes on Saturday suggested Robb was the only frontbencher capable of restraining Turnbull’s ego, and should be his shadow Treasurer.

Robb was having none of that yesterday, but regardless of what happens to the Deputy position — Julie Bishop would probably hang onto it on gender grounds, however much she would reject that sort of tokenism – Robb should be in a significant domestic portfolio, where his skills would be applied to something more high-profile than (correctly) demanding that we sell uranium to India.

And, however much it will upset the state distribution, they should take the opportunity to remove some underperformers like Pat Farmer and Bronwyn Bishop and give up-and-comers like Simon Birmingham a crack at a shadow ministry. Greg Hunt should also be given more responsibility, even if the ETS will keep him busy in 2009. After nine months, performance has to start to mean something.

And, as Alan Ramsey might say, another thing. One suggestion in the weekend press is that, after he’s given the mythical “clear air” (think Tantalus’s fruit and water), Nelson might agree with everyone that he’s a dud and give way voluntarily to Turnbull. That is, a nice, orderly “leadership transition”. Nelson’s got guts and doggedness and has taken a lot of pain while he’s been in the job. He deserves to fall in battle, not withdraw from the contest to spare everyone’s feelings. There’s more honour in that. Turnbull should challenge him and the sooner the better for the country and the party.