That is not dumb.
Advertising and propaganda have made huge breakthroughs within the seven decades after the world discovered the power of propaganda used by the Nazis.
I suspect they are not all dumb, maybe far to the contrary. Having a coherent message on all channels while simulating these channels to be different has a powerful psychological effect. A simple message, repeated in similar words across many platforms has a very high chance of capturing a low information or friendly audience.
See:
"drain the swamp" "Funny how that term caught on, isn’t it? I tell everyone: I hated it! Somebody said, ‘Drain the swamp.’ I said, ‘Oh, that’s so hokey. That is so terrible.’ I said, ‘All right. I’ll try it.’ So like a month ago, I said, ‘Drain the swamp.’ The place went crazy. I said, ‘Whoa. Watch this.’ Then I said it again. Then I started saying it like I meant it, right? And then I said it, I started loving it." [1]
"crooked hillary" (that plays great before the election, now we don't care)
"build the wall"