Guardian: Barack Obama The last time Barack Obama took a chance on Copenhagen it ended in abject humiliation. The president hopped on a flight to the Danish capital to join a campaign by Oprah Winfrey and his wife, Michelle, to try to win Chicago the right to host the 2016 Olympic Games. But the Obamas’ reliance on their high-voltage star power fell flat. The International Olympic Committee eliminated Chicago in the first round of voting. When Obama returned to Washington, …