We’re looking at it from the wrong side. FIRST, SECURE THE BORDERS! Then decide who stays and who goes. Some of them are keepers. Many of them are throwbacks. But throwin’ ‘em back now will just result in their slippin’ back in under another name.
I would not give them the right to vote. Anyone willing to violate border laws has surrendered their right to vote. Do we give felons the right to vote? No.
Let them work out what to do with the 12 million who are here. One thing they should consider:
If these squatters violate a crime and the crime merits a fine sufficient to transport the criminal back across the border, they pay their way back. How much is that? $300? Once in the criminal justice system, their fingerprints and DNA will be on file, if they get caught back in the country. Then, instead of being sent back, they get prison time. Word will get out that going back into America risks a prison term for at least 5 years. Then, deportation at the end of sentence.
Of course, seal the border to make it almost impossible for new squatter to sneak across. I would build a physical fence layored with a technological fence (drones, aircraft, proximity detectors and infrared cameras) and National Guard troops along areas most vulnerable.