The 1st part of your post makes a lot of sense, but I have to disagree with this part. I travel regularly to non-border states and, trust me; you cannot swing a dead cat by the tail without hitting a non-english speaking Mexican.
True, we were the "Melting pot" but that was a long time ago, under so much different circumstances. The government didn't support families, each had to go out and work for their subsistence. Aside from the language, it's the $$ taxpayers spend. If an illegal crosses, has a child born on American soil, she can qualify for a medical card and we foot the bill even though she is here illegally. (At least that's what I've been told). Also, having other languages is fine but it would seem important that there must be one uniform language. It's unreal the public monies that go to teach students who are ESL (English as a second language). If we went to another country we wouldn't be afforded the same.