Learning from history is tough, even for those who remember it.   Parallels are never exact.  The importance of each difference between then and now is a judgement call.   Consider a darkly hilarious cartoon by Jen Sorensen:

Yes, the resemblance of the armed guard to a Nazi storm trooper is as subtle as a sledge hammer.   Fine by me.   Maybe it will overcome the American propensity for historical amnesia and wishful thinking.

Much to my dismay, Hillary Clinton is the only Trump opponent who might conceivably be elected.   The progressive purists who disdain supporting Clinton are confident that something like what happened in Germany in 1932 and 1933 could not happen here and now, with a Trump victory.   Yes, our traditions of liberal democracy are stronger than those of the Weimar Republic.   The pertinent question is not whether our traditions are stronger but whether they are still strong enough, after years of relentless assault from the pseudoconservative coalition of bigots and plutocrats that controls staggering amounts of dark money and has already taken over the GOP.   Dammit, the answer is not obvious.