re: While that's certainly a good strategy if you mean to learn English
I would hope the gov was talking about people that intend to stay for extended periods or become permanent residents. Were I to decide to move to Mexico to live I would immerse myself in the Spanish language. I'd certainly still speak and listen to English from time to time but there's nothing like necessity to foster learning.
I think his remarks were benign and more in line with caring about the welfare of immigrants than disparaging. Maria Shriver would kick his butt otherwise.
Art