What you need to be asking is who are they. The common conception is that their all Hispanic who 'crossed' to get some low paying job. That is not the case, it appears from studies that most illegals are overstays, they came to visit and stayed. A former employee of mine has his own computer consulting firm....he has no visa, no "papers"
As long as I have been aware of the content of conversations around me I have been hearing about this "tragic emergency' at the borders, that's 7 decades of living, six hearing about this. Any moron can figure out that "great" does not apply to a country that allows such a condition to fester for over half a century - only for the sake of keeping a "wedge issue".
If Americans wanted the problem fixed it would have been long before this. Capable to the point of annoying boasts of glory you can single handedly conquer Japan AND German, fly to the moon, and invent the most power killing machines the world has ever known, but you can't fix what is, in essence a mere clerical problem.
Don't worry, nothing Trump will do will change anything, it will merely make the lies sound more true.
Please DO build that wall....along the north too. You don't want those cheating Canadians stealing your jobs would you?