There's a "great-great-great-grandson" of an American president who lives in a hovel and delivers pizza for a living.

See http://www.nytimes.com/1999/01/03/nyregion/our-towns-impeachment-as-legacy-for-pizza-guy.html?ref=andrewjohnson .

That guy's presidential ancestor is Andrew Johnson, who "was the first U.S. President to undergo an impeachment trial" and "is commonly ranked by historians as being among the worst U.S. presidents". (http://en.wikipedia.org/wiki/Andrew_Johnson )