... that all voters are as dumb as they are. They assumed wrongly.
They assumed that once Idiot Boy was installed in the White House, no questions would be asked as to how he got there. They assumed wrongly.
They assumed that the populace would be easily distracted by shiny objects. They assumed wrongly.
They assumed that an idiot would stop being an idiot once faced with the responsibilities of the presidency. They assumed wrongly.
They assumed that no one would notice that a pussy-grabbing, bloviating, bullshit-spewing pathological liar had plopped his lard-ass in the Oval Office and would, accordingly, say nothing. They assumed wrongly.
Note to Trumpsters: Idiots always assume wrongly. If only you'd known that going in.
And trusted bad people. And some were likely caught up in the web of blackmail and corruption, and felt like they had to go along with it.
And I'm sure many of them believed, and still do, that if they pulled off a coup and turned the country into a dictatorship, they wouldn't have to worry about getting caught.