As a thought exercise, how could the illegal situation be resolved?
Figure 1st step is to require US proof of citizenship before a specific date, or a valid Green Card, with the application records before a certain date, to be eligible for any US or state benefits. Ban social benefits/ETF transfers for any not conforming.
Set a sunset date with a reasonable amount of time for self-deportation. RFP for carriers to fly or ship out deportees.
Those not self-reporting are put in detention camps until an agreement is made with country of passport.
Do a Liberia/slaves type plan for those cases still not resolved.
Any illegal entrant to US is banned from travel to US for life.
Pretty tough stuff. Will have to be necessitated by proof of an existential threat to law-abiding US citizens, for example, covert terrorists and anti-American behavior.
Could not be done in a politically derived government, IMO. Would have to be under martial law due to an existential threat and illegals declared as non-uniformed combatants against the US. IOW, a complete shutdown and do over, but with square1 still being the traditional interpretation of the US constitution, pre a specific amendment. 14th would be a good point, I think.
Is it even doable at this point?