> exterminate "undesirables"

This isn't accurate. As I understand it, the theory was that the state should control "the race". Which means that it would decide who has children with whom, control marriages, who educates them, how, where and why. In other words, control everyone, everything, to get a perfect society. The goal being improving/purifying "the race" further. The thing that makes it different from a bond movie is that it's not a singular "evil genius" type of guy but 20-30% of the population trying to do that.

I pity whoever had children in Germany in the 1930s because that must have been terrible, no matter how German you were. Granted, the experience was vastly different for Jews, but it wouldn't have been a good experience for anyone.

The "first" holocaust, so to speak, the beginning, was the state euthanizing psychiatric patients with no hope of recovery (real ... and imagined, like gays). Then they went after the long-term ill, like people in coma or with serious illnesses (this was before widely available antibacterial treatments so there was no shortage of such people), and generally everyone who was a burden, eventually including everyone who was perceived to not be 100% dedicated to the state, in the opinion of the idiot bullies that worked in the police and the various state services.

Like in the Soviet Union, what the Nazi state did was give people like teachers, police officers, army, gestapo (let's call it their FBI equivalent), ... absolute control over normal citizens. Needless to say, this power was not really used for the stated purpose, but to allow sadistic bullies to utterly control everyone around them. God help you if your kid did better in school than the assistant principal's kid. To let scared politicians torture 100 people to death because someone let their dog poop on their niece's law. To let moral busybodies in the state arrest all children and have them perform hard labor in a camp because there was a girl that got pregnant unmarried (Nazis arranged marriages), or had a kid with someone other than the arranged partner. To let bureaucrats take away children from their parents "because they didn't raise them right", and then (usually) torture those children (given the motivations of those people, like the assistant principal referenced above, I think you can "understand why" they would torture those children). To have the mayor declare that the fact that 10 people died from starvation because there's no food in any store, and it's the fault of that evil enemy, not the fault of him diverting all the food to a party in his garden for his wife's cat's birthday.

The thing people don't seem to understand is how the human mind works. Under such circumstances, you might expect people to revolt, but that didn't (and doesn't) happen. People wouldn't revolt, not even the Jews being deported. What do people do when they're tortured ? The vast majority ... try to join the torturers. That part is not different from the Taliban to the Soviets, to the Holocaust, except perhaps in scale and just how far they went.

That's why such a system can keep existing and continue itself. It's victims want to join, not revolt. That's why these systems can grow. In the Soviet Union, such a system existed for a further 30 years at least. Ask a few ex-Soviets, the bureaucrats were let loose there for much, much longer than in Germany.

The important thing to realize is that the US police/FBI/CIA/... contains many people that aren't all that different from their counterparts in 1930s Germany and, given the chance, they would do the same.

But of course, people have forgotten. We just need more laws, more powers, more investigations, to make society just and to make sure those damn rich bankers don't get away with everything, don't we ?