Nazi Germany was capitalist. Fascist regimes are capitalism for the upper classes. IBM made the early "computers" that kept track of the concentration camp numbers.
And because fascism is capitalism for the upper classes, taken to its extreme - libertarians in the US have something to do with it. If libertarian politicians can convince people that nativism is a good idea, property rights are paramount, and dismantling the government is necessary - what is behind that agenda is the freedom for the powerful to do what they want, and be as greedy as they want, with no oversight. That's not freedom for the people. That's them abusing liberty for power and money. Get the Bible Belt on board, using some apocalyptic survivalist propaganda that benefits the NRA, ramp up nativist fears about "outsiders" and bingo bango, they have useful idiots to follow fascist aims, against their own best interest.
Libertarianism is inherent in US politics, even in neoliberalism - and it's part of the root problem. It's a hangover from the Wild West. It's not actually about freedom for the people. It doesn't lead there. It leads to chaos. And then to Marshall law to put it in order...at the expense of minorities. It's "Cowboys and 'Indians'" but even worse.