Birtherism -- the belief that Barack Obama was born in Kenya, not in the United States -- pretty much died last year when the White House released a copy of the president's long-form birth certificate showing he was born in Honolulu on Aug. 4, 1961. After that, the number of Americans who doubted Obama's place of birth dropped dramatically. But not to zero. In recent days, there has been a mini-resurgence of birther talk, from Arizona, where the secretary of state questioned Obama's eligibility to be on the ballot, to Iowa, where some Republicans want to require presidential candidates to...