As the US president flew home from Copenhagen, his unsuccessful attempt to convince the International Olympic Committee to choose his adopted home city was widely seen as a blow to his credibility. Joined by his wife, Mr Obama gave an impassioned presentation – the first by a US president on behalf of a city bidding for the games – in which he hailed Chicago as "the most American of American cities". There had been widespread expectations in the US that the president's star power would prove all-conquering, so there was shock when Chicago was the first city to be eliminated....