Boris Johnson is nothing like Churchill, a view with which my friend Andrew Roberts concurs. But in the 20-odd years I have known Boris, I have often been struck by his similarity to John Wilkes, 18th-century politician, journalist and catnip to women. A wit and a showman, Wilkes, who denounced European entanglements and championed the rights of the electorate over parliament, was the first politician to achieve celebrity status.