A very old joke. My great aunt told this to me. Back before anybody had heard of the fellow whose portrait I've pasted here.
There once was a family of potatoes who thought of themselves as socially very lofty. They looked down on television as a new fangled technology filled with blow-hards, whether human or potato.
Anyway, the family had a pretty good life on the farm. Until one day the daughter decided she was going to elope with a young spud (I think that was my great aunt's pronunciation) who didn't live up to the family's high-brow notions.
In fact, this young spud had even appeared on television.
"You're going to have to get this marriage annulled," yelled father.
"He's just a commen tater."
Get it? Common'tater? Commentater?
Ah, never mind.