This is the world we live in though, aka reality. There's 10-15 million undocumented immigrants living here. Part of the argument is what to do with them. You can't go back in time and change that. Also do you agree with Trump that we need to spend billions on a wall and put forces all alongside it to enforce the law? Also what about migration from Mexico being in the negative in the present day? Things aren't as cut and dry as it's wrong, there's gotta be a solution.
you dont need to round up 11 million, you merely enforce existing law more thoroughly, which ironically is what obama started doing in the beginning, people get caught up in immgration in all kinds of ways, and obama was deporting 400,000 a year, in fact that IMO that is why you started seeing a negative migration to mexico. So all you have to do is increase enforcment, to maybe 750,000 a year and a lot of people will self deport because the cost of being an illegal immigrant becomes to high, in 10 years with stricter enforcement and self deportation you willl have a huge reduction in illegal immigration, you dont gotta build a wall and you doint have to round anybody up