From Colby Cosh, Edmonton, Alberta:
This is concerning a comment you made in a recent thread on your site: "I have NEVER had an immigrant taxi driver in Chicago (invariably African, Indian, Middle Eastern) who was not tuned to NPR. Make of it what you choose."
A while back I noticed a similar phenomenon here (in Edmonton, Canada): most of the time, the immigrant cabbies (which is to say, 95% of them) have CBC radio--which has pretty much the same texture, programming mix, and values as NPR; the mutual influence is fairly obvious--when they have the radio on at all. Eventually I worked up the nerve to ask a Chinese-Canadian cabbie about this. He gave me to understand that he was trying to learn good Canadian English from the radio, so it was only natural that he would listen to the pan-(English-)Canadian state broadcaster. And, indeed, it struck me immediately that this was a perfectly appropriate choice.
Virtually every country outside the United States, including mine, has a BBC-style state broadcaster with a hypothetical mandate to deliver the news neutrally, and another mandate, stated or unstated, to promote a relatively "pure" or at least portable educated-speaker version of the national language. (The BBC of course operates alternative Gaelic and Welsh networks, but in these cases the mandate to teach learners a "good" standard version of Gaelic or Welsh is probably more important, not less.) NPR is not in any official sense an American government network anymore, but self-evidently it thinks of itself as "national", as quasi-official and authoritative, and as speaking in a politically "neutral" way to all Americans; many immigrants may not even know that it has no formal status. Basically, when they arrive in the U.S.A., I would assume they probably recognize (or are directed to) NPR as the language-learning aid and pronunciation authority they are looking for. It is not, according to this hypothesis, preferred because it is particularly intelligent or liberal or eclectic, but mostly because of the N in NPR.
This is pretty much just a guess, though.