What is Churchillian about him is that he absolutely refuses to meekly comply with the party's line, if he disagrees. Churchill went so far as 'to cross the floor' Can't see Boris being driven to that. Some years ago the Party made sure he had a party minder to watch over him when campaigning in the presence of the media. When someone asked him what he thought of gay marriage he said "I don't know...' then to the hapless minder' What IS our line on gay marriage?' Not waiting for the minder to reply to this mischievous, mocking enquiry, he went on to say that man with woman man with man, man with dog..well , it's a free country, what does it matter what they do etc etc before saying he was in favour. Brilliant and refreshing, and typical.
That's what the public like; someone who is not the cowed party hack, with the party line, but who thinks and speaks for himself, and who has a certain charisma.