THIS IS THE SECOND TIME YOU HAVE BEEN ASKED. Show me anywhere in the U. S. Constitution where it says anything about 1). illegal aliens or 2) non-U. S. Citizens?
What makes you think that only illegal aliens speak Spanish? Plenty of American citizens, including natural born citizens, speak Spanish as their primary language. The issue has nothing to do with citizenship, and everything to do with free speech. But you already knew that, you're just trying to make BS arguments by playing stupid.
Not only that, but the constitution applies to all people within the US's borders, regardless of citizenship or legal status. Using stupid arguments such as yours serves only to strengthen the side of those who, unfortunately, do not rational immigration policy or the enforcement thereof.