I think it's worth noting that the wave of fascism that swept the world during the early 20th century coincided with radio and television being widely deployed.

This may be correlation that does not imply causation. But demagogues had, for the first time, a way to reach into people's homes directly with their messages all the time, if they had access to microphones, video cameras, and broadcast towers. And it was a mechanism that excluded the ability of any antithesis messages to reach people on those same channels (once the government had control of the channels). Mussolini and his ilk certainly knew how to take advantage of these tools.