Not any more! Hard to argue that it is unknown.
However there are probably hundreds of laws passed since the end of the 19th century to militate the "progressive" counterargument that many laws passed since have invalidated whatever understanding once existed regarding citizenship; unconstitutional or not.
I respectfully disagree. Why dont you ask some of your friends what they think of the unique, 10th Amendment-protected power of the states to regulate immigration, including to pardon illegal immigrants, and post some of the responses that you get?