Unfortunately, cynical hypocrisy and pathological denial is far more common on both sides of the divide than is deliberative and informed understandings of the other side. I have not yet looked at responses to your post (I assume there are some) but no doubt you have triggered a clichéd list of objections. Here is my checklist of the usual:
"I am not against border control, but it's too expensive and I just know it won't work to use walls, large fines, detention in camps, "encounters" (arrests) beyond the border, raids...yada, yada, yada. But ya of course I am against illegal migration".
" I am not in favor of illegal migration, but can't we use less judgmental and nicer terms like "undocumented migrants"?
" I am not in favor of illegal migration but it's impossible to send any back".
" I am not in favor of illegal entry but it's too harsh to segregate families and children after they are caught."
" I am not in favor of illegal workers, but we can't send them back because our economy will collapse without enough yard workers, dishwashers, nanny's, and illegal migrant farm labor."
"I am against illegal migrants so why not give everyone caught or turning themselves in at the border legal documentation making their crossing and employment legal".
"I am for legal immigration, so we ought to give amnesty to all to make them legal and then raise the legal limits to immigration to 20,000,000 a year because more is better."
The point here is that those holding the above opinions are not against self-approved entry, they just want to make sure that the millions who wishes to move here can, and they fill out the paperwork needed to provide them jobs, benefits, and protection from deportation... ie a legal status and a "path to citizenship".
For those who are lying to themselves, and/or to us, they keep insisting they are not for open borders, because they actually support open borders with paperwork attached.
Go figure.