No doubt Nazis did take Jim Crow into account, but my point is the Nuremberg Laws & subsequent discrimination against Jews & other "outsiders" was based on European, not American history & practice.

E.g. the wearing of yellow badges (including the Star of David) has its origins in the Fourth Lateran Council of 12 15 (Muslims were also so required). Jews in France were emancipated by Napoleon in 1791. But given that Germany wasn't unified until 1871, many of the German states dawdled in emancipating Jews. E.g., Holstein & the Free City of Frankfort not until 1863.

Black people in the United States, on the other hand, were citizens due to the 14th amendment, which also granted them equal protection under the law. I realize that didn't always, or even usually happen. For example, the Mississippi Plan of 1875 held that every white man ought to control at least one negro vote. Voting rights were (& are) the key to black emancipation.

In Germany, with Hitler as sole Fuhrer, voting was not a particular issue. Citizenship was. The Nuremberg & subsequent laws were more of a return to European policies of the pre-Enlightenment than to anything pertaining to the US. As I wrote, I think the Nazis' main concern with Jim Crow was to use its existence to charge hypocrisy at any criticism leveled their way.