The footage reveals that once Michelle Obama is announced, a part of the people start booing. We have to mention that the two ladies were present in an effort to promote the "Joining Forces" program, an initiative aimed at helping the US military.
A response from the White House arrived as the news spread across the world, with officials claiming that the cheering sounds were greater than the booing ones, as ABC News writes. You can draw your own conclusion by watching the adjacent video.
PS: we don't know how this could help, but Russian Prime Minister (and ex. President) Vladimir Putin was also booed while attending a sporting event recently.