It might be said that there's a lot of compulsive believing going on in this thread, in both directions.
Trump's victory has a great deal less to do with discontent with the system than people believe. After all, in case you had forgotten, he was the candidate for the Republican Party. Does anyone seriously believe that after eight years of a Democrat president that this didn't help lift him up to the presidency? Or, put another way, that he would have done as well running as an Independent? Nonsense. And yet his supporters and his opposition both tend to ignore that. Trump didn't win from a standing start (and, in fact, didn't win at all in the popular vote, a fact that doesn't take away from his victory but is still relevant to contextualise it).
So we have people who supported Trump assuming that 63 million-odd Americans also do, as in support and agree with Trump the man, rather than Trump the Republican not-Clinton not-Democratic presidential candidate. And we have people who opposed him making the same assumptions, and fearing for the state of modern politics that there are so many racist misogynist basterds in the US right now.
No matter how you approach it, believing that Trump is popular or supported be a majority is both a compulsive, wrong and dangerous belief. So yes -- the article's core argument is in a sense correct. Shame it was so badly-written, and a little too focused on the compulsive belief of Trump's supporters in favour of his opposition.