Dear Melania,
It's true, Donnie isn't Hitler, but that's mainly because Donnie is too venial by comparison; too obsessed strictly with himself rather than with some abstract ideological volk. However, he is just as dangerous in many respects because he presents himself as someone who does not respect limited government and government by law. Instead, he presents himself as someone who wants to govern by mob rule and cult of personality. He is also thin-skinned and has already expressed the intention of using the organs of government to settle personal scores. In that way he is very much like Hitler, in the trivial but still dangerous sense.
In short, accusing Donnie of being like Hitler is an insult to Hitler.