Yep. Your post gets to the heart of this. It’s not a federal issue. People forget that this country was founded in a way similar to the EU. That is, the colonies were like “countries” with an overarching government to protect the border around the whole thing, and protect the rights of individual citizens within the member countries (e.g. the first and second amendments over rule any state’s constitution), and activities that cross state lines. A good example would be that Kentucky can’t invade Tennessee.
.
Technically, the 14th amendment ended “states rights” by placing the states under all of the provisions of the first ten amendments.
It was the only way to ‘justify’ the Civil War.