Pretty good - and short - look at television use during the 1964 US presidential campaign. While a lot of coverage is given to the infamous Daisy ad, other ads are covered as well.
One of the most interesting subjects that has information there but isn't addressed in great detail is how people's recollections change. People remember the ad being more specific than it was, or airing, more, though it really only aired once, while getting a fair amount of news coverage after that. Beyond that, there were disagreements later about who came up with the ad and the fairness of the ad, all of which didn't seem to be issues earlier.
(That reminded me of seeing an interview with Tommy Ramone, where he takes credit for writing most of every song he is asked about. Other band members would probably disagree, and they might all have points.)
The later feeling that the ad was a dirty trick and unfair seems unfair in itself. That may be partly that people remember the ad as being more specific than it was, but it was clear that it was a Goldwater reference. However, it was clear because of his own words, frequently quoted and reinforced.
I am happy to accept that some of Goldwater's dangerous statements were based on ignorance and the reality of what the new technology could do, but he was an influential senator and presidential candidate; is it too much to ask that he become informed before spouting off?
That last question seems to have obvious parallels to today, and that is kind of the interesting thing. In 1964. most people were against war mongering and even the health risks of above ground testing, and to some extent even the racism overt enough to not officially support racism but to go against anything that would combat racism.
Knowing what comes after 1964, with more coded language to disguise the racism, fear-mongering through crime, the war on drugs combining them both, and Reagan learning how to use all that and sound optimistic, yeah, the seeds were sown. It took some fine-tuning, but there is a lot of Goldwater in Trump, just worse, and it matters because the voters are worse.