The myth of the current anti-immigrant crowd is "these people never learn english". Quite the opposite, they follow the same progression as virtually every other immigrant group. The first generation, usually already well into adulthood, maintains weak, if any, english skills. The next generation, even if they weren't born here, usually learns both languages, and are truly bilingual. The subsequent generations slowly lose the original language. What is slightly different right now is that there has been a fairly consistent, long term immigration of latin based languages into the US, covering several generations. The result is that we "hear" an almost constant community of nonenglish speakers. And there is some (not as much as claimed) retention among the 3rd generation of the original language (probably closer to "spanglish" actually).

The original point however had to do with the similarities, culturally and economically speaking, between the California situation, and Scotland. In both cases there isn't much to compare. California is much more significantly "different" from the entire country east of the Mississippi (save significant chunks of Florida) than Scotland is from England. (Quite honestly, N.I. is "more different" than Scotland is). Economically, California is a "legitimate" economy in its own right, and would be a significant loss to the US, and a major player on the world stage (probably qualifying for G20 status). Scotland, not so much.