It's illegal in most respects. Quotas are as well.

Of course, you can signal your nationality on your application, and the university may take that into account, but it's a hidden process, and it's up to each university. Furthermore, a university does not have to use the official US government classifications.

It may decide to break down Latino and Hispanic students into a non-European ancestral category. I don't think there is a designation for Arabs at most universities.