I think that universal healthcare would be the key to ending undocumented immigration, and more importantly, wage evasion by employers. It is simple: documented immigrants get free healthcare, the same as any citizen. This would allow the state(s) to track the workplace activity of immigrants, and in turn be able to collect taxes, enforce fair wages, and hold businesses accountable.

This also has the effect of allowing citizens to have equal job opportunities when compared to migrants, because both are paid the same. Companies will naturally turn to hiring citizens, simply because they are closer to home. Everyone who isn’t a ghoul wins.