People don’t overstay their visas and live illegally in a country because they have good options. They do it because they are desperate and have no hope of gaining legal immigration status through the fucked up process the U.S.A. has.

This will kill more people as they attempt to cross the border through dangerous routes.

Increase crime as criminals move in to “assist” the desperate people and make a profit.

https://en.m.wikipedia.org/wiki/Coyote_(person)

It will also cause a decline in the tourism industry, well more than it already has.