Get rid of them.
1. Build the fence, patrol the fence, survey the fence
2. E-Verify
3. SSN checks to root out ID theft by illegals
4. Random sweeps
5. Inspect employers for illegals and punish violators
6. Work with the states instead of suing them (unified front)
7. Apply pressure to sanctuary cities/states
8. Voter ID laws
9. Investigate welfare cheating by illegals
10. Enforce the laws already on the books
11. Jail time!!!!
In effect, you “sour the milk” and make illegals self deport. It’s worked, even when a modicum of enforcement is applied (see Alabama). Sometimes the mere hint of “will this be the day I get caught/discovered” is enough.
If you have a harder time finding work, can’t get the cover as you did in the past, feel you have to look over your shoulder, it’s a deterrent. Psychological is just as important as physical.
Once you secure the system, THEN and only THEN do you start the debate on immigration (how many, who, skill sets and what restrictions). If the legal process needs more money/materials then so be it.