On last night's Mad Men on AMC, the character Henry Francis - an adviser to moderate New York Republicans such as Gov. Nelson Rockefeller and New York City Mayor John Lindsay - is heard saying that he won't let "His Honor" go to Michigan "because Romney's a clown and I don't want him standing next to him."

The reference was to then-Michigan Gov. George Romney, the father of current GOP presidential frontrunner Mitt Romney. "His Honor" is almost always a reference to big city mayors; at the time the current season of Mad Men is taking place, Lindsay is a Republican. (Based on the opening scene of the season, with Young and Rubicam idiots dropping water on civil rights protestors - which actually happened - as well as other clues, the year is 1966.)

In 1971, Lindsay changed parties and in 1972 he unsuccessfully pursued the Democratic presidential nomination. Political advisers bad mouthing competitors is nothing unusual, but clearly the reference upset Tagg Romney, the grandson of the late governor, and the son of Mitt.

Wrote Tagg Monday morning, retweeting a tweet from a Politico reporter: "Seriously, lib media mocking my dead grandpa? @aburnspolitico: "Well, tell [him] His Honor's not going to Michigan. Because Romney's a clown and I don't want him standing next to him."

This was followed by Tagg tweeting: "George Romney was as good a man I've ever known. Inspirational leader, worked for civil rights, promoted freedom. We need more like him."

Francis, played by actor Christopher Stanley, is not an actual person, but rather a fictitious character on a television show. He is married to Betty Draper, who also does not exist in real life.

-Jake Tapper