It Congress wants to change the law, they can. It's up to congress, not the administration, to make law. For decades it seems Congress has largely abdicated its legislative responsibility in exchange for the political ease of letting the administrative state, and the courts, make the law.

Just because something has "precedence" doesn't mean it's right. Banning gay marriage had precedence, but that didn't make it right. Slavery, segregation, all had ample precedence. They were still absolutely wrong then as they are now.