the fact that they weren't expelled means the was lax enforcement in the past, of course if they're going to change it and make it strong again and abolish sanctuary cities and what not, they should explore an amnesty for those who have always held jobs and have been in the US for longer than 10 years and have no criminal record and have american children, but it's not a god-given right they have, they know they've been living in the US illegally.
Actually the fact that illegals can have american children is just weird too. That should be fixed as part of the package as well.
Grandfathering in the older illegals, and cleaning up the act for the future, meaning strong enforcement with immediate arrest and deportation if identified, no birthright etc. would be the most humane way to go about it.
The stasi accusations are overblown, the problem with the stasi is that it was an instrument of dictatorship. Reporting on breachers of democratically estabilished laws would not be on the same level at all. Calling the police when you see a crime does not make you a stasi snitch, it's expected behaviour. This is like accusing someone who doesn't want immigration to be literally hitler. It's intellectual abuse.
His absurd proposal of letting citizens catch illegals is blackshirt level stuff which is even worse than stasi surveillance.
Eminent domain still means spending money to compensate land owners, too expensive.
Ad-hoc flexible solutions in the difficult areas of the border, with surveillance, collaboration with land owners etc. depending on the situation, would be a better way of going about it.