WITH a seven-point lead in the polls a few days before voting, the race for America's presidency is now Barack Obama's to lose. John McCain, meanwhile, claims that the polls are inaccurate and that his opponent's lead is much narrower. Gallup polls taken since 1952 suggest that the candidate leading with around week to go is usually victorious, albeit by a smaller margin in actual votes. But the inaccuracy of polls (or perhaps the fickleness of voters) was demonstrated most startlingly in 1980, when a lead for Jimmy Carter turned into a thumping victory for Ronald Reagan, perhaps thanks to the televised debate that took place after the opinion poll. In 2000, George Bush's lead evaporated and he scraped into office despite winning fewer votes than Al Gore.

AP