David Starkey is outspoken, often outrageous and frequently contemptuous of any views which do not accord with his own.
As far as TV producers are concerned, this attitude would be acceptable if he was of a left-wing persuasion.
Unfortunately for them, his views are formed far out on the right and often come swooping in with devastating effect because Starkey is both formidably intelligent and dauntingly articulate.
This presents the TV folk with a dilemma, because though his presence makes any programme compulsive viewing, they lose credibility with their right-on peers.
David Dimbleby’s expression on a recent Question Time reflected the dilemma – an agonised blend of professional admiration and political loathing.