Obama could be a trump card should he decide to carry his support for his hometown to the IOC meeting on October 2 at Copenhagen where the final decision will be made.
Former British Prime Minister Tony Blair and Russian President Vladimir Putin lobbied IOC members in the run-up to votes on the respective bidding that led to the London 2012 Summer Olympics and Sochi 2014 Winter Olympics.
"Obviously the presence of Barack Obama could be a positive point for Chicago's candidacy," former IOC president Juan Antonio Samaranch said.
Spain's top sport official, Secretary of State for Sport Jaime Lissavetzky, said he does not see Obama having a significant impact despite the success for Putin and Blair from their appearances.
"I have my doubts that Obama can have such an influence," Lissavetzky said. "I think that the members of the IOC are quite apolitical."
The IOC panel will meet with bid officials and tour proposed venues for a Chicago Summer Olympics as the US Midwestern metropolis known as "The Windy City" challenges Tokyo, Madrid and Rio de Janeiro to host the 2016 spectacle.
"I am very engaged and excited about showing them the city," bid chief Pat Ryan said. "We will make the city come alive for them. It is hard to envision it unless you see it for yourself."
As for Obama, Ryan is glad for his prior shows of support but more worried about the details of the bid package.
"His election has put Chicago into a very bright light. He is both very popular inside and outside the United States," Ryan said.
"He supports our bid and came to a rally in Chicago. But we have to keep it in perspective and keep our eye on the ball and do what we have to do to win the race."
Two potential headaches beyond Ryan's control appeared to have calmed ahead of the commission visit.
IOC and US Olympic Committee leaders talked last week about redistribution of money issues and Ryan was confident they would reach a deal.
The IOC wants the US group to take less money even though the most of the largest sponsors and television deals that finance the IOC come from US firms, while US Olympic officials want to avoid cuts after slashing staff to trim costs.
A change atop the USOC also came seven months ahead of the IOC vote as Stephanie Streeter, a member of the USOC board of directors, was appointed interim chief executive in the wake of Jim Scherr's resignation that took effect Tuesday.