headbanger

One who dances by violently shaking the head in time to the music.

One who enjoys heavy metal (rock) music, to which this sort of dance is usually performed.

A violently deranged, extreme or fanatical person; a nutcase.

A silly or eccentric person.

A political hardliner, especially an obstructive one.

We would therefore paralyse ourselves for no good reason other than the propagandistic appeasement of the Daily Mail, the Sun, my noble friend Lord Hamilton and a few other headbangers in the Commons on the Conservative side.

Corbyn's lack of ambition would turn out to be one of his great selling points. He was the man at the margin: a headbanger for most and a man of principles for a few.