At around the age of 7, Barack Obama saw a picture in

The debate that followed shed light on how much you have to know, and how much you have to forget, to become German in some eyes, and laid some ground rules for Dejagah's inclusion and integration. "Whoever represents Germany, whether a native German or an immigrant, has to identify with the history and culture of our society," said Ronald Pofalla, the general secretary of the conservative Christian Democrats. "If he does not want to do so out of personal political reasons, then that national jersey should be removed."

A quarter of a century later came the claim that General Andrew Jackson was the offspring of a union between a "common prostitute and a mulatto man". Eight years later came the "issue" of vice-presidential candidate, Colonel M Johnson's black slave mistress - Julia Chinn - nearly derailed the ticket with Martin Van Buren.