I think it's more than just that. Yes, that article rings a lot of truth to it, and I saw that with my own eyes when I worked in the States a couple of years ago.
I have another theory, in that the mainstream media, who are mostly Pro-Democrat with all the hollywood actors showing their support, are doing everything in their power to throw shade at the republicans and Trump, but in doing exactly that, they keep on making the Republican followers more Pro-trump.
What's worse is that the talk shows in the States keep on employing foreign presenters like John Oliver, Jim Jeffries and Trevor Noah, instead of promoting their own people. Yeah, those guys are funny, but purely because they are not American, they lose value into the things they say and talk about.
From an outsider's point of view, I always had this view of americans as being these loud, obnoxious, overweight fools, and I had that opinion since I was a kid. Isn't Trump the poster boy of exactly that image? And isn't that exactly why so many of his fellow americans support him?
My dad always said that if he lived in the USA, he would have been a republican, regardless of the person running for office. He's a very conservative guy, and isn't big on change (which old person is?), Which made me think that many Americans are probable brought up like that the same way, in that they are Republican-Americans. And would rather support Trump, than be on the same side as the Deemocrats and their more liberal viewpoints.