hobby horse

Riding any anti-Obama hobby horse is endemic to today's GOP.

There was much difficulty and great variety in the motions which the hobby-horse was expected to exhibit.

This is the work of a scholar, but of a scholar mounted on a hobby-horse of unusually vigorous mettle.

But Mr. Bidder, dying to mount his hobby-horse, and not caring how, said it was not at all curious.

I am now at work at my hobby-horse essay on Expression, and I have been reading some old notes of yours.

Forgive me scribbling this way; but when a man gets on his hobby-horse he always is run away with.