A one-way radio broadcast is not a dialogue; in fact, we have much closer to realtime dualogue with leaders today, despite greater scale (yes, its still moderated by intermediaries, but its much more rapid and much less wrapped up in the ability to tell different stories to different audiences without information rapidly flowing between them—politicians still try this, sometimes, but it tends to fail, and increasingly to fail very quickly.)

Dialogue?

I suppose the FDR had better writers, and was better at sticking to his scripts.

But there were a lot of people who referred to FDR as "that man in the White House" rather than use his name. And Edmund Wilson quoted somebody at a dinner party in the 1930s, where someone denouncing Hitler was answered with "That's going too far. You're talking about him as if he was Roosevelt."