Rory Bremner has his own election battlebus tour, with a show of two halves, part stand-up and part question time, which is taking him around many of the marginal seats. I took part on the post-interval panel at Dartford's Orchard Theatre last night.
All impressionists are bound to worry about the passing of political generations. Bremner told yesterday's Telegraph that he fears a political "character crunch" could threaten his livelihood.
He raised laughs with reprises of all of his popular favourites - Blair and Bush, Michael Howard and William Hague - while Obama, Sarkozy and Berlusconi featured on the international stage.
Of the leaders now fighting the election campaign, there was quite a bit of Bremner's deep booming Scots Brown, who visited the Queen, sparred with Blair and claimed to have saved the world.
Bremner has spoken about his difficulty capturing Nick Clegg, though we were talking in the interval about his many tongued multilingual fluency, and Bremner might perhaps begin to introduce Nick Clogg and his facility to connect in fluent Dutch.
But what struck me was how little David Cameron there was in the Bremner stand-up last night. Apart from a little bit of the Great Ignored speech, the would-be next Prime Minister seemed conspicuously absent.
Bremner must find that audiences respond much more to routines on Michael Howard, John Major and William Hague - though there was also a fair bit more of old Vince Cable and Peter Mandelson than Cameron last night too.
I am no expert on political comedy but my amateur musings are to wonder whether the Cameron comedy enigma may be two-fold.
Like Clegg, perhaps he does not have that many distinctive features, beyond a somewhat generic nice poshness, which might provide the trademark signature around which an impression is built
But might this also reflect something about public politics and the Cameron persona? In his fifth year as leader, there are as yet relatively few strong public points of resonance or connection which seem to shape people's responses to David Cameron - whether these are positive or negative.
It is frequently reported that focus groups can spontaneously recall the cycling and chauffer incident, as well as the huskies photo-op, but often not very much else.
So the contrast with the campaign was that, when it came to the comedy routine, the Tory leader was almost as invisible as his Shadow Cabinet. George Osborne got a brief mention, but no impression. There were some B&B jokes but it would be pointless to attempt to impersonate Chris Grayling when so few of us would recognise him in the street.
There was one notable exception. How grateful Rory Bremner must be for Cameron's faithful retention of those Yorkshire vowels of William Hague.