What the most important thing "he" said is, is a matter of opinion and, of course, mine is different. "Widely known and supported" is not proof of anything.
Your error is in not understanding, then mixing and confusing words. I said that I can't check the text of the book but the third party precis is liable to be erroneous, at the very least.
I think we all know Trump et al complained about the 2020 election. What's new?