I'm not sure what you mean. I'll try and give you my thoughts on what I think you're asking.
Previous administrations put policy in place, or ignored existing policy, that allowed for the flood of millions of illegal entries into their country.
The current administration has made efforts to reverse this, the border has now been secured much more effectively. Phase 1, stop the inflow, has largely been achieved. Going out on a limb, I suspect phase 2 of this is to find and deport those most problematic (criminals, openly displaying bad intentions, etc). I suspect concurrently with Phase 2, the admin is working on a path to resident or citizenship status for the many people who arrived illegally but have turned into contributing members of society.
Bottom line, unchecked mass illegal migration can cause havoc on your country as we can see with many EU nations dealing with their own migrant problems.