First off he's not Hitler. No one who was Hitler could have that many Jews in his family and recognize Jerusalem as the Israeli capitol.
Second off, he's not Stalin, the lefts current fallback position. If he were, most of the Democrats would love him and besides he hasn't sent anyone to the gulags he hasn't built. No matter how richly they might deserve it. The walls he wants to build are specifically to keep people out, not in.
Now imagine a figure whose existence inspires fierce loyalty among his followers and terror among his enemies. A figure who causes insanity to afflict his enemies just by getting up in the morning. A figure who seemingly cannot be stopped but only delayed.
Trump is Cthulhu!