Many times one's prejudice is not manifested as a slur or poor treatment. Many times one uses some other issues that are pretty much a stand-in for said prejudice. This type is much harder to eradicate because it is not easily called out as such.
English speaking requirement for immigrants?
Here is the reality. One rarely gets a eureka moment when trying to convince another to modify their stance on a particular issue. Changing programmed beliefs and indoctrination occurs with patience and allowing the subject to answer the questions on their own.
Even as the caller agreed with me on mostly all that I said about the original settlers having instituted their own culture and language as opposed to adopting what was already here, he was in the short term unable to insist on immigrants learning English.
It was clear from the conversation that like most Americans, the caller was not an inherently bad person. He was made to believe that there was something wrong with an immigrant bring a piece of their culture. Instead of seeing it as an addition, something to cherish, something to enjoy, he saw it as a threat. He cloaked it in his concern for their economic well-being.
It is ironic because it never seems to upset too many when discussing ethnic neighborhoods like Italian, German, Russian, Hungarian, or others. Why? Because hue to too many is much more significant than one's inherent culture either overtly or otherwise.
I am convinced that ultimately the conversation with this guy will remain in some remnant of his brain. While he did not immediately change his stance, there will be other cues activated that will help lead the way to his atonement.