COPENHAGEN (Reuters) – The first lady’s powers of persuasion will be as important as the president’s charisma if the Obama effect is to bring the 2016 Olympic Games to Chicago.

The White House announcement that President Barack Obama would fly to Copenhagen to appear before the International Olympic Committee has given the Chicago campaign a lift in the final few days before Friday’s vote.

Yet with the president only due to arrive on the day of the election, Chicago’s bid team is cautious when it comes to predicting how much of an effect he can have in the tight race with Madrid, Rio de Janeiro and Tokyo.

They certainly do not expect him to do the sort of intense campaigning then British prime minister Tony Blair did when he helped persuade members to choose London for the 2012 Games, or Russian president Vladimir Putin when he helped win the 2014 Winter Olympics for outsiders Sochi.

Instead it will be down to First Lady Michelle Obama to lead the lobbying effort for her home city after her arrival today.

“The eyes of the world were already here but now they’re really shining brightly in Copenhagen,” Chicago bid leader Patrick Ryan said at a news conference at a platform built on a Copenhagen swimming pool yesterday.

He added: “It obviously changes many things. The President is coming to the city, people are very excited that he’s coming and that Michelle Obama is coming.

“But we don’t know, nobody knows, if it impacts the race. The voters will determine this.”

Obama will become the first sitting U.S. president to address an IOC session. Michelle Obama will also address the session and she is expected to hold one-on-one meetings in the Danish capital.

“Michelle Obama will be doing that (meeting with members) over the next couple of days,” Ryan said.

“We’re so thankful (to the president). We’re not comparing this to Tony Blair or Mr. Putin or other presidents. We don’t want to get into the politics. This is about sport. It’s about the Olympics. It’s not about the influence of one individual.”

That message, that the Olympic Games are about the athletes rather than politicians, was one Ryan and Chicago Mayor Richard Daley came back to time and again on Tuesday.

“I would just say that this is not about competition among heads of state,” Ryan said. “This is about cities that would be the best host cities for the Games. It’s all about what’s best for the athlete.”