They all say America is not good. Why is the problem of illegal immigration in the United States so serious?

Illegal immigrants are mainly Mexico. The tragedy of Mexico is that it is too far from heaven and too close to the United States. Mexico's greatest tragedy is that it is too far away from God and too close to America? Building a wall in the United States will not change the gap between Mexico and the United States, but will only increase the gap between Mexico and other South American countries.