I assume you have some steps in mind? I mean, obviously, the war on drugs currently is a miserable joke of a failure, and anything that is just another iteration of the same type of steps is probably doomed to the same type of horrendous consequences.
As for building a wall... IT WON'T WORK. What you have to do is change the circumstances that make people want to come over, to risk incarceration and whatnot. Bring Mexico up instead of bringing America down. And, honestly illegal immigration numbers are down significantly over the last decade, at least according to the latest numbers I have seen.