Well, thanks to his own words, of course, I am now pretty sure that Trump is a Nazi. How so? He believes in eugenics--that some people are innately superior to others:
Of course, most of this video is him bragging about how smart he is. And, yes, we can contest that, but I think it makes a decent case for the continuities in Trump's behavior and history. Is it worse to be a true believer than a con artist? Actually, yes. Because a con artist might not follow through once he achieves what he wants. A true believer is something else entirely.
There are plenty of good reasons to oppose Trump already, but a candidate buying into the core tenets of Nazism is just so far beyond the pale that he needs to be criticized without pause, opposed with all energy, and defeated utterly. Alas, the US is a polarized political system, so many Republicans will simply vote for their party's candidate regardless of how awful he is. The good news is that Trump is self-destructive, lacking discipline and focus, despite being so "superior."