Well, saying yes or no would be a pretty dumbed-down kind of answer, compared to the fullness of the situation.
Compare the language and thinking of Jimmy Carter or Dwight Eisenhower or FDR to the thoughtless illiterate should-be-in-prison “grab-‘em-by-the-pussy” clown who was given the now-called “POTUS” seat last year.
Or listen to a good Martin Luther King speech.
Listen to recordings of the above people talking and reading speeches, and listen not just to how thoughtful, resonating and sense-making what they have to say is, but that they actually seem to fundamentally understand what they’re saying. Contrast that with practically any modern American politicians.
And/or try a similar exercise with the news media. Certainly the television news media is a corporate-dictated retarded ape circus compared to what it was like 40 years ago. Much of the print journalism is that way, too. And not only is it dumber, but it’s often clearly slanted or misleading or false or makes no attempt to cite its evidence for its statements.
Not that there wasn’t plenty of stupidity and drivel and lame speechmaking in the past. There was, but now there’s a pretty bleak desert, particularly in the US media.
Fortunately, there are also many intelligent and new things being said and understood, so there is much more going on than just mental decay, even though it can often feel that way when looking at conspicuous examples.