The reason we ended up with a coalition government is that the public did not want Labour back for a fourth term but they did not want the old Tory Party back either. So they chucked in the Lib Dems and said ‘you lot sort it out.’

Analysed coldly, David Cameron should have won the last election, when you consider the economic crash, the battering Gordon Brown was getting, the length of time Labour had been in power, MPs’ expenses, and the shiny new Tory leader getting such an easy ride.

But for all Cameron’s smart marketing skills, voters were frankly unsure about whether his so-called decontamination of the brand was anything more than a, well, smart marketing trick. The coalition was a way of putting the Tories on extended probation.

Public fears that it was all a marketing scam have been borne out, with Cameron moving from slogan to slogan, ‘top priority’ to top priority, make-it-up-as-you-go policy to make-it-up-as-you-go policy (what on earth was that energy tariff thing about?) and in the absence of clear and credible strategy, issues like Andrew Mitchell and the copper, and George Osborne and the ticket guard get disproportionate attention and with disproportionate impact.

But there is one other factor in Mr Cameron’s current troubles that has attracted very little attention from the commentariat. That is how Nick Clegg has ceased to act as a chief spokesman for the coalition as a whole.  That is working to Mr Clegg’s benefit and Mr Cameron’s disadvantage. Without Clegg constantly reminding us that he is part of the show – his Lib Dem colleagues have also gone more low profile – we are left with the impression of a bunch of Tories, and a pretty second rate bunch at that, in charge.

In the early heady days Clegg was out there happily defending the indefensible, from the broken pledge on tuition fees to the NHS reforms for which they had no mandate to the austerity cuts which along with Cameron he was always happy to blame on Labour.

I always felt he was taking on an oversized share of the load, and allowing himself to be used as a lightning conductor by the Tories. It is a lesson he appears to have learned. He is, I suspect, done with the fagging for his Old Etonian boss.

It is widely thought that Clegg, to use Ed Miliband’s word for Andrew Mitchell, is ‘toast’. I am not so sure. Certainly the tuition fees broken pledge will do him real damage at the next election, assuming he is still leader. But the Lib Dems’ share of the vote at the local elections was not as catastrophic as it might have been. Added to which my sense is that he has shown greater resilience than his coalition partners. For that reason above all, I have found my respect for him growing while my respect for Cameron diminishes every time he pops up on telly with yet another ‘look at me’ observation or activity reeking of tactics not strategy. (Tomorrow stand by for a speech on a new ‘tough but intelligent’ crime strategy. Presumably this is an admission that so far he has been tough but stupid, or soft but stupid, who knows?)

Sensibly, Mr Clegg has started to think a little more of his own and his party’s interests as we move into the second half of the Parliament.

People have grown weary of Lib Dems making threatening noises about Tory policy positions and then doing next to nothing to stop them. I sense they are now taking a different tack – just let the Tories do their own thing, and try not to be overly associated with such epic incompetence. So far, so good.