Okay lets make it legal for all Mexicans that want to come to the US. They are not illegal any more, do you still have a problem? Thought so.
Your assumption is correct. I would still have a problem with this solution.
The problem is the volume. A volume that robs the recent immigrant of his chances to prosper and profit. A volume that robs our society of it's ability to assist the less equipped to prosper.
Immigration is the lifeblood of our society and culture. It brings diversity and a competitive spirit. Massive, unregulated migration victimizes both the immigrant and the society. It Balkanizes the immigrant leading to hysterical, unwarranted bigotry and robs our existing society of its ability to sustain the values and traditions that have served us so well.