To your last point, Brown Vs. The Board of Education prevents racial segregation in schools, Loving vs. Virginia prevents state laws against interracial marriages, and Atlanta Hotel Vs. The US was the landmark finding that upheld the legitimacy of the Civil Rights Act of 1964, specifically the clause that prevents businesses from discriminating based on protected classes.

So to answer your question at large, we DO have actual laws on the books that are supposed to protect historically targeted minorities, but at any moment these rogue malefactors could declare any one of those laws unconstitutional as they've shown they have NO regard for precedent.

Basic rights for people who aren’t white dudes were mostly imposed by court order. That’s the reality. We have laws, it’s just that those laws were written at a time when personhood didn’t really apply to anyone who wasn’t a white man. And if no one who you consider a full person is capable of being pregnant, you’re not going to think to put in a right to abortion explicitly, even if it’s a basic requirement for equal citizenship for the female sex, because women (and trans people) aren’t really people…and so on.

Edit: I realize this is mostly due to the weird semi-religious fervor Americans have for our Constitution and government system.

TL; DR: We’re running Modern Democracy 1.0 with a Frankenstein covering of patches, while other countries just upgrade whenever they need you.