BBC News' Adam Brookes in Chicago: "The shock of Chicago's elimination was greater for the fact that it came in the first round. And greater for the fact that President Obama had taken valuable hours from his packed and tense political schedule to travel to Copenhagen. His legendary powers of persuasion will be said to have failed him, though in reality it will be Chicago's bid that failed him. Nonetheless, this is a moment which allows the president's detractors to allege waning prestige on the part of his presidency. And it will raise questions about the political advice that he is receiving."