Barack Obama will travel to Copenhagen on Thursday to back Chicago's bid to host the 2016 Olympics, senior adviser Valerie Jarrett said today. The president will be joined by Michelle Obama and his education and transportation secretaries. Chicago is bidding against Tokyo, Rio de Janiero, and Madrid, but none of the four cities is seen as a favorite ahead of Friday's vote. Japan's new PM, Brazil's president, and the king of Spain will be lobbying as well. (More Chicago stories.)