I don't think what you're saying is really the point, however. I'm not aware of any suggestion that either administration was "like" Hitler's. Not in the way you're thinking of it, in any event. There is a saying, attributed to Mark Twain, (but likely a false attribution), that history does not repeat, but that it rhymes. Which to me implies there are templates of behavior that can be expected to play out in a similar fashion, given similar conditions.
Something you may have noticed myself emphasize often enough in the Trump threads, is that Trump appeals to the baser instincts of his core followers. And when there are forces, such as intense cultural changes, occurring in a society, this causes degrees of stress, anxiety, fear, anger in segments of a population, that can be taken advantage of by clever demagogues. Like Trump. This is, after all, basically what Trump is doing by suggesting "Middle Easteners" are hiding in the caravan. He is playing on the "fear of the other", and fear in general. This is a common tactic of an authoritarian. It does not mean that there is an exact equivalency, lurking around the corner, between Trump and Hitler, and that someday we can expect mass atrocities by Trump. It's not suggesting that. What the whole comparison has been about is some see similar conditions between the two eras and nations resulting in a similar reliance on an authority figure promising to restore their nation's greatness, and creating "others" for segments of the population to focus their fear and anger.
That's really very different then the way I believe you are perceiving the observation. But correct me if I'm wrong.
As Timothy Snyder put it: Post Truth is pre-fascism. We are in a Post Truth era, and we have a president that substitutes alternative facts for facts. Today, for instance, he utilized a dog whistle for his core followers by issuing a tweet in which he talk about "this 'bomb' stuff", the dog whistle being putting "bomb" in quotations in order to suggest the so-called MAGA Bomber was a false flag operation. Or so I would interpret that use of quotation marks.
“Fascists despised the small truths of daily existence, loved slogans that resonated like a new religion, and preferred creative myths to history or journalism. They used new media, which at the time was radio, to create a drumbeat of propaganda that aroused feelings before people had time to ascertain facts. And now, as then, many people confused faith in a hugely flawed leader with the truth about the world we all share. Post-truth is pre-fascism.”
― Timothy Snyder,
On Tyranny: Twenty Lessons from the Twentieth Century
“As observers of totalitarianism such as Victor Klemperer noticed, truth dies in four modes, all of which we have just witnessed. The first mode is the open hostility to verifiable reality, which takes the form of presenting inventions and lies as if they were facts.”
― Timothy Snyder,
On Tyranny: Twenty Lessons from the Twentieth Century
“Fascists rejected reason in the name of will, denying objective truth in favor of a glorious myth articulated by leaders who claimed to give voice to the people. They put a face on globalization, arguing that its complex challenges were the result of a conspiracy against the nation.”
― Timothy Snyder,
On Tyranny: Twenty Lessons from the Twentieth Century
“Americans today are no wiser than the Europeans who saw democracy yield to fascism, Nazism, or communism in the twentieth century. One advantage is that we might learn from their experience. Now is a good time to do so.”
― Timothy Snyder,
On Tyranny: Twenty Lessons from the Twentieth Century
Now, this is not scare tactics, Joe. This is not fear mongering. Trump practices both. But this is instead simply an effort to learn the lessons of history. It is most unfortunate, IMHO, that comparisons with 1930's Germany cannot be made without folks assuming a type of comparison is being made that suggests Trump=a future Hitler. No, it is to simply suggest other people in other places have placed their faith in leaders without realizing the mistake they are making...
I think all of Snyder's thoughts above address the comparison in a far more meaningful and thoughtful manner then is much more commonly assumed whenever the comparison does arise in conversation. And in particular, I find a great deal of meaning in his very simply observation that "post truth is pre-fascism".