Although that might technically be unfair to AOC and Pelosi. I don't believe either of them are actually fighting to directly end American sovereignty.
After you import half a billion people from South America, and another billion from China and Africa and the Middle East, where and how do we see the benefits?
Would you give every person on Earth the right to vote in our elections? Or just the billions who migrate to what used to be our country? Or would there just be no more voting?
I personally don’t think open borders is a realistic idea. Even today, there are several private militias that voluntarily patrol the southern border with Mexico. Many people have this natural desire to protect their lands. I believe that in an an cap society, the border would go from government controlled to private militia controlled, and in lonely areas where people owned land that wasn’t patrolled they might use other means of protecting it; maybe a sign stating there are land mines or something like that. There wouldn’t be much reason to come though, without any of the guarantees that the safety nets now offer babies born here, etc. Closed borders make sense overall, but I suppose someone might want employees or a wife and there would need to be official points of entry for those who could prove they were there to spend money on a vacation. I support tightly closed borders in our current setup.