And dnd, I think you've mixed up speaking plainly in order to reach a larger audience and speaking down to people because you've figured out how to sell yourself to a particular demographic after being on reality tv for so long.
Is there that much of a difference? 'Speaking plainly' so the recipient can understand and 'dumbing down' so the recipient understands you has the same effect. The difference is based not on the speaker but the listener, who will call it 'dumbing down' if it's not necessary. The target audience for simplistic grammar would avoid calling it 'dumbing down', because that would be an insult to themselves.
Essentially, potentially demeaning language is determined by the audience, not the speaker. For example, if Dora The Explorer was marketed to people in their mid-40's instead of 40 months, that would clearly be talking down. Hell, it's talking down for most seven year old kids. But it's not talking down for the four year old, because that's the level the show needs to stoop to to ensure that the target audience fully grasps what's happening. If a 40 year old happens to watch Dora, for whatever reason, does that mean the show's writers have now been 'talking down' to their audience? If parents watch a show with their children, does that mean the show is insulting the parents if it doesn't include bits the kids have a hard time following?
If Trump needs to speak in simple terms and use strong hawker's rhetoric with punchy sentence endings in order to find and inform his audience, let him. The numbers indicate it's working in his favor, which means it's not talking down in the same way that Blue's Clues wasn't talking down when they asked toddlers where the giant paw print was on the screen and then stared into your soul for a full ten seconds before moving on as if nothing happened. IT'S ON THE F***ING CHAIR, STEVE!
Was the guy's name Steve? I feel like it was Steve.
Anyways, what matters is that there's a balance that has to be struck. The lower you go to be inclusive, the more you offend the outliers at the high end of the curve. Based on the evidence I'm seeing in those around me, where people who formerly avoided politics like a plague are following the trump trail wholeheartedly and people who would never talk politics before are now actively researching and engaging, The level Trump's picked seems to be effective.