Commonalities would be insecure property rights, universal healthcare and “free” education and other benefits (Hitler offered greatly subsidized vacations, for example, and built a massive vacation complex on the Baltic), the lack of individual rights, the “Allmacht” of the government, the extensive use of secret police and informers, economic stagnation outside of imperialism. This is a short list.
I will note that even taxation is not a power granted directly to the Federal government, if memory serves, by the original Constitution, outside of, I believe, tariffs. The power to force people to buy something, or to reallocate wealth, is categorically antithetical to everything all the Founders believed in.
And “Socialism” is not a new idea. The Romans had their version of it. It bankrupted them, and it corrupted their people.