Per Don Y:
When you *can't* find a claim to that affect, you can reread:
The [candidates of the] right thinks their base are idiots and dumb
down their rhetoric to simplistic ideas that they *hope* their base
can swallow, without thinking.

In the documentary movie "Nixon's The One" - where actors re-create oval
office scenes using the exact, precise dialog from the Nixon tapes -
there was an encounter between Nixon and an financially-successful
religious entertainer named Oral Roberts.

Both agreed that, when they were talking to the public, they were
addressing the 12-year old ("Reading comprehension of the
seventh-grade") mind. This is at about 12:40 of Episode 4.

Scroll to 12:30 and you'll ease right into it.
https://www.youtube.com/watch?v=PlHZGoVx0vg
--
Pete Cresswell