TV basically changed how elections work in this country. Before TV you had to be able to talk the part, you needed substance since all anyone knew you as were your words, but after TV you just had to look and act the part.
You can dive deeper and really say that radio and even the telegram started to ruin public discourse. Yeah, Trump isn't even the first to do this. Look at Reagan, he got crushed in his debates, but "won" because he looked the part.
When the Radio Act was enacted, Herbert Hoover who was the Commerce Secretary at the time believed it to be a tool for learning and nothing more, but sure enough in a few years it became a commercial product with the motive to sell the population shit. People slowly stopped caring about being intellectually simulated and started to care more about being entertained. Television was the real nail in the coffin though for reasons that I could go on for a while about, but some of that was helped along and the foundation laid with radio and honestly the telegram.
I don't know why 1984 is at the top of the best seller list, people should be reading Brave New World; it's a hell of a lot closer to the world we live in right now.