That is the hardest question to answer for me as to why folks support Trump.
While I'm registered unaffiliated, I recognize that at this point I lean Dem. (I would say that's more due to the rightward lurch of the Pubs in the last 15 years, but that's not really important.)
But if the Dems were running a liberal version of Trump - someone who was an extremist, who tried to overthrow the peaceful transfer of power, who used the office of POTUS largely for their personal gain, and who has shown no respect for the institutions of government nor democracy - I would have no problem voting for a Pub for President - certainly someone like Mitt Romney and very likely even someone like Nikki Haley or Chris Christie.
And it's not like anyone paying a minimum of attention should not know who or what Trump is at this point. It's clear who he is and what he wants to do. The only understanding I can take from it is that folks prefer a fascist who threatens the integrity of our government to a slightly-left-of-center Dem.