The Olympic Games draw the attention of the entire world. It's a situation that is completely irresistible to a politician. All of that "limelight" practically demands that they somehow get into the act and get their "message" out there.
The International Olympic Committee (IOC) does its best to keep politics out of the Olympic Games, but that's nearly an impossible task. The first time that the Olympic Games were used by a politician for personal gain was in 1936 when Hitler used the Olympic Games that were held in
Berlin to further his cause.
The athletes themselves rarely express their political opinions. The athlete's objective is the competition rather than furthering a political cause — usually. During those same Olympic Games in 1936 that Hitler used to further his political cause, Luz Long (of Germany) helped Jesse Owens (an African American) win the long jump, at the expense of his own silver medal.
There was one occasion, however, where the athletes themselves were involved in using the Olympic Games to further their own political agenda. It happened during the 1968 Summer Olympics in Mexico City. Two black track and field athletes from the United States, Tommie Smith and John Carlos, while standing on the victory stand after the 200-meter track-and-field race, performed the "Black Power" salute.
The IOC was not amused. The then president of the IOC, Avery Brundage, gave the United States Olympic Committee a choice. They could either send Tommie Smith and John Carlos home, or withdraw the complete track and field team. The two athletes were sent home.
Politics are still alive and well in the Olympic Games today, but rather than political statements being made during the games, governments opt to boycott the games altogether or they refuse to allow their athletes to compete against athletes of a rival political faction and depend on the media to get their message out.
For example, the government of the Islamic Republic of Iran specifically orders its athletes not to compete in any Olympic heat, semifinal, or final that includes athletes from Israel, and the media publicizes the reason for the lack of participation by the Iranian team.