The advent of the TV Politician
Before he became president, in 1959, John F. Kennedy wrote an article for TV Guide magazine.
"Television is a medium that lends itself to manipulation, exploitation, and gimmicks. Political campaigns can actually be taken over by the public relations experts who tell the candidate not only how to use TV but what to say, what to stand for and what kind of person to be."
When Kennedy decided to run for President in 1960, he had a famous television debate between himself and Senator at the time, Richard Nixon. Kennedy was a good looking, dynamic, personable guy. Nixon simply wasn't.
In the polls, Nixon lost the debate on TV; he came across as dour, darker, a little too much sweating, it didn't go over well. However, if you were one of those people who listened to the debate on radio, people thought in the polls, that Nixon won the debate. This heralded the advent of the TV Politician. And perhaps, the decline of American, if not, World politics.
Marshall McLuhan video on media