It’s about how many people I want flooding my homeland. It’s about whether a nation can be a nation without borders… (No, it cannot.) It’s about the fact that we cannot support every person in the world who decides to they want to live in the United States. Just as England, France, Germany, India, Argentina… and even Mexico could and should not be expected to embrace every single person in the world who wants to move there.
Limited immigration has an important place in our country. Currently, there is virtually no limit. See the math in this simple video on YouTube.
A slightly different take on it, more depth to the point.