As a person who grew up an hour from the border in California, I think Spanglish is a language. It's a pigeon language that makes it possible for teenagers to communicate at school as well as with their parents and extended family. Many people that speak Spanglish know Spanish as a spoken language and not as a written one, because they learn it at home, but don't study it in school. When I was in elementary school, we were separated into an English speaking and a Spanish speaking class, and we didn't interact much until about 4th grade, once most of the 'Spanish' kids were fairly English fluent. Obviously, English speaking students didn't have to worry about becoming Spanish fluent. I found out later that learning English was made priority number one for those kids, and English learning came before things like science, math or history. For kids like this, speaking English (in the US at least) is basically non-negotiable. But Spanish is an avenue of keeping in touch with one's roots. So combining the two is a way of walking a very complicated cultural divide.