A few weeks ago the Los Angeles Times published the findings of some research into the use of English by Spanish-speaking immigrants. In my view, however, the results were not surprising or unusual. What seemed unusual was that the Pew Research Center investigated the language habits of Hispanics, only to conclude that by the third generation, most children of Spanish-speaking immigrants are primarily English speakers. Perhaps this study was undertaken to quell people's fears that Spanish is overtaking English in some parts of our country.
On a similar note, the LA Times earlier covered a lawsuit concerning the Salvation Army's firing of employees for speaking Spanish on the job. Democrats and Republicans have been divided on the issue of whether or not it is discriminatory to fire workers who do not speak English in the workplace. In the Salvation Army case, two women lost their jobs because they were speaking Spanish while sorting clothes. The question of how essential it was that they speak English is the issue. In addition, how far should the government go in protecting people's right to speak other languages in the workplace? Should it be illegal for employers to fire someone for speaking other languages at work?
While I do believe it's fine for people to speak other languages in the workplace, I can imagine situations where it is essential that everyone speak the same language. For example, in hospitals, there are large numbers of medical personnel who are non-native English speakers. I learned from a nurse from the Philippines, who was taking my TOEFL course several years ago, that the hospital that had hired her required a certain score for her to get permanent employment status. She thought it was a waste of time since she had the nursing skills to do the job. However, I was relieved to hear that there was some English requirement (though I'm not sure that the TOEFL test was appropriate for a medical job). If a non-native speaker doesn't understand or misunderstands the patient, the doctor, or a fellow nurse, major mishaps could result.
If you want more to chew on, check out 'The Web of Language', a blog by Professor Dennis E. Baron at the University of Illinois at Urbana-Champaign, where you can find more thoughts on the position of English in the USA and elsewhere in the world.
Finally, is American English under threat? No, I don't think so. Yet throughout our history, as various immigrant populations grew and spread, and we heard their languages on the bus, in stores and supermarkets, and in the waiting area at the dentist's office, many Americans got a bit paranoid that they might need to know a language other than English. This anxiety continues today, but in time, that fear will change to pride in the fact that the majority of Americans will speak more than one language.