The "birthers" doubt that the president is really a US citizen. The White House is now publishing his birth certificate.

Calm down, please: Obama must prove that he is a real American. Picture: dapd
"Birther" – the word is not yet in any dictionary. But in the U.S., it is dominating – and poisoning – the early stages of the presidential campaign. The word is derived from "birther." It describes people who doubt that Barack Obama is a U.S. citizen. Presumably with the political calculation of picking up potential voters on their resentments. This week, the "birthers" managed to get the White House to release the president’s birth certificate.