Hitler was absolutely a symptom of a material/historical conditions of post-WW1 German economic deprivation due to the Treaty of Versailles as well as the long, deep undercurrent of centuries of European antisemitism. That's...like the mainstream consensus of historians for decades. No one serious considers him some extraterrestrial figure who invented the Holocaust as alien technology. But this is a load-bearing difference we see between the two main camps in this thread. On the one side we have people who refuse to apply systemic thinking to current political/ideological problems and are myopically and maniacally only focused on the flame currently in front of their face, and on the other side we have people who are curious about the underlying conditions that keep causing these fires all around us. So when the latter group says "Hey, it's actually bad that Kamala is sanitizing/normalizing Republicans and arming the genocide against Palestinians" the former group lashes out at them like the doctor who told the emphysema patient to stop smoking. If you don't have the mental aptitude to apply systemic thinking and connect smoking to lung disease, it just looks like the doctor is telling you to stop enjoying yourself.
Yeah this is the operating belief of Resistance Liberals who weren't politically aware prior to 2016 when Trump activated their political consciousness. Being historically illiterate is the only way one could look at the Republican Party pre-2016 and think that it was trending in a significantly different direction than it has ended up right now. The conspiratorial thinking you're referencing is one of the most deeply embedded features of not just Republicanism, but the American mind itself. Hofstadter wrote The Paranoid Style in American Politics in 1964. This is the Party of Joseph McCarthy and the John Birch Society. Trump didn't invent any of this shyt. If you want to blame any one figure, blame Mark Zuckerberg.