From a press pool report on June 6, 2008:
Sen. Barack Obama made a surprise public appearance in Chicago today, speaking for about 5 minutes just after 12 pm at a downtown event to rally Chicagoans around their city's bid for the 2016 Olympics. Chicago is one of four cities being considered for the Olympic Games (the others are Tokyo, Rio de Janeiro, and Madrid). “It's a good time to be in Chicago,” Mr. Obama started off.“White Sox are winning. Cubs are winning. And Chicago's going to win the 2016 Olympics and Paralympics. And your senator, he's winning too.”
From the Chicago Tribune, November 21, 2008:
It didn't take long for Barack Obama to start playing a significant role in promoting Chicago's bid for the 2016 Summer Olympics.About 15 minutes into Chicago's Friday presentation of its bid plans to the general assembly of the European Olympic Committees, the president elect gave an 85-second videotaped address to an audience that included some two dozen International Olympic Committee members. ... ``While I am unable to be there in person, I wanted to take this opportunity to speak with you because I deeply believe in the Olympic movement and have long supported hosting the Olympic and Paralympic Games in my home city of Chicago.