The only 'divisiveness' I see is the distinction between those who are here legally and those who are not.
It sure seem that even in the 'sanctuary cities' the latter have become a bit of a problem, fiscally, socially, and in terms of criminal activity above and beyond their mere presence (which is a crime, too).
Sending those who have breached our borders, in defiance of the peace and dignity of a sovereign nation, back to wherever they came from.
Otherwise, over 11,000,000 lawbreakers would be allowed to be scattered among us, often at our expense. How would that be a good idea?