Then you are under some serious delusions. The anchor baby is a tactic used by those with no legal status in the US. If amnesty is granted, there will still be two or three billion poor, potential illegal entrants around the world who would very much benefit from having an anchor baby.
You think millions of poor Mexicans and others further south - who are not physically in the US - will just magically forget about the anchor baby advantage if amnesty is granted to illegals already in the US? They would still gain all the welfare and government support benefits an anchor baby would make available to them.
Illegals already here who might receive amnesty, and the, potential future illegal entrants who could gain benefits with an anchor baby, are two totally different categories of people. Amnesty does nothing to diminish the lure of having an anchor baby for the billions of poor outside the US.
Excuse me for confining my point to the “Mexican” issue. You are correct, I did not include poor people in Malaysia who come to the U.S. to have anchor babies. Therefore, you are correct.