As promised, I wanted to post a more detailed explanation of language policy. This is going to be very long. I am sorry for that, but I couldn't avoid it. And I will be oversimplifying.
There are three main issues when we talk about language policy: the propagation of the majority language, the place of foreign languages in a society, and the protection of minority (i.e. regional) languages. As you can tell from my previous posts, you can't talk about strategic language policy and planning without getting into cultural assimilation, discrimination, civil rights, and ultimately human rights.
The most interesting book I found on the subject was François Grin's Language Policy and the EU Charter for Regional or Minority Language Rights. So I am drawing heavily here from his work and in a way, turning it around. This book takes a policy analysis approach to understanding language policy and uses the charter as a case study, which he meticulously dissects. The EU charter was aimed at protecting regional languages. But I am going to use those concepts to talk about building a general language policy.
Language policy, like most policy-making, is supposed to be a systemic, rational, theory-based effort to modify the linguistic environment. Good policy always has as its main objective the improvement of the overall welfare of a society. We know the objective of bad policy, which is usually self-serving to its creators. Language policy is, therefore, public policy. It seeks to take a cold look at reality and then to shape that reality.
Policy makers operating in a democratic system, cannot and should not impose preferences on people but they should provide for people's preferences to be heard through some democratic process. Even if a policy can't directly improve welfare, it can do so indirectly by creating, maintaining, and developing the necessary conditions. So if you take the protection of minority languages, with the goal of maintaining the linguistic diversity of a nation or region (in Grin's case, of the EU), then you have to develop policies that foster the development of regional languages. This also means that you accept a certain degree of state intervention, otherwise, as LTG and RBR point out, you leave everything up to market forces.
Proponents of this idea assume that welfare is more improved by market forces than state forces. And the question you ask is whether or not state intervention can ensure the "right" amount of language diversity. LTG's concern focuses on market failures (insufficient information, high transaction costs, imperfections in market structure, the existence of public goods, the fact that some markets can't exist, externalities, and as of late, repudiation of the assumption of rationality) If language diversity or the lack thereof is good and a market failure occurs, then state intervention is acceptable. So in LTG's thinking, you need to have an official language to propagate it, the implication being that it is under threat somehow. But what is missing in the "official language" debate is some hardcore policy analysis and formulation. What is the strategy behind this sudden desire to adopt an "official language" at the federal level? This is my biggest problem with most of what Congress has done. There seems little consideration of the consequences, and no real explanation of any serious goal behind such a move.
You have to think about these policies with a methodology of objective evaluation. Is the goal of an "official Language" to protect English from being overrun by foreign languages? Is it to move toward an English-only system? If that is the case, what protections for regional languages like Cajun or Hawaiian will you put into place? How will you treat new, non-English speaking immigrants? Is your goal it to build national unity? If so, is language really the best avenue for achieving that? Do we have studies that we can use to measure language learning in this country? What do these types of studies tell us? Do we even understand what our immigrant population looks and acts like? (I don't think we do, by the way.) Have we talked to that community to get their views on the issue? What happens when neurological science tells us that after a certain age, the brain's ability to take in a second language is significantly diminished? Will we have the courage to promote a policy that may be unpopular on its surface, but is supported theoretically by the research if that means achieving our stated goal? Will various stakeholders be served by the policy? What options do we have and what are the merits of each option?
None of that has been done in this debate about "official languages". I agree with LTG that we need to have some sort of solid language policy in this country. I don't think "official language" is the correct policy on its own nor do I think it is even worthy of the word policy because it isn't formulated or based on any policy analysis or process. It is, in my view, a soundbite.
We have never developed a coherent language policy or strategy in this country outside of the Pentagon. We have a combination of negative rights, rights that limit the actions of the state against the individual (you can't arrest someone for speaking a foreign language) and positive rights where the state intervenes to ensure rights(the law requires provision be made for a lawyer and interpreter to make sure the state isn't abusing its power). Negative rights are often supported by an underlying layer of positive rights.
We do not require foreign language education and we have never thought much about "official" languages. We have benefited from the policies of other nations, such as Europe, that require foreign language education from young ages. Since "they all speak English" why bother learning their languages, right? When we needed people to help us listen in on or communicate with our "enemy" , thanks to our large immigrant population, we always found speakers (native or heritage) of the needed language. There are over 300 languages spoken in the U.S. about half of which are indigenous. Some 52indigenouss languages are now extinct. So there was never any active attempt to halt the use of foreign languages in our governmental systems but no desire to discourage them either. It was up to market forces or natural selection to determine the fate of a language. This is starting to change. In the next 10 years foreign language learning will be required in our public schools. And we will adopt policies to promote this just as we have with math and science. It's already started. Why? Because suddenly the military cares, which is what usually happens to motivate major policy shifts in this country.
Conversely, there will be even greater national attention on teaching English. Because guess what? It ain't just about the language, it is about proficiency in the language. This means the ability to take in information, understand it, and critically analyze it on the fly. Since most people can't critically analyze in their native language, how can they be expected to do it in a foreign language? If you can't multiply and divide, how can you do algebra or calculus? So along with the basics of a language, you have to learn how to think critically. This means there will have to be a greater emphasis on communication and critical thinking in English. And, as all of us who speak foreign languages can attest, it takes years and a lot of hard work and dedication to master reading, writing, and speaking a language. There aren't any short-term fixes or silver bullets here.
ESL is a whole specialized field now. And it is growing. California has been on the front lines of that movement for years. And foreign students, often with little formal education at home, cannot be expected to master English overnight, especially if they live in communities where there is a lack of opportunity, motivation, or desire, the three requirements for the survival of a language. And an English-as-official-language policy alone in these communities won't change that because the problems are linked to poverty, Iiteracy, health, etc. In addition, you have to treat the whole person. The immigrant brings with him baggage from home that has to be respected and addressed. So any policy would have to be paired with programs in a given community to address underlying causes.
Does having an "official language" make it easier to justify the massive resources currently devoted to ESL education? Yes, which is why the state of California along with 27 other states and the Virgin Islands have declared English as their official language. 5 states and territories of the US are officially bilingual, the Marina islands is trilingual, and for kicks, Pennsylvania was bilingual until the 1950's when German was removed as an official language. For a more detailed look at this go to Wikipedia. To become a naturalized US citizen (on the books anyway) you have to demonstrate the ability to read, write, and speak English. Any amnesty program would further dilute that requirement. I just want to add that legislating English as an official language is one thing when it is a law unto itself, it is another when it is attached to an immigration bill.
Currently, there is a movement throughout government to inventory and professionalize our "language assets". We can no longer rely solely on immigrant and heritage communities to do the work of government and intelligence. Government is partnering with universities to fund language institutes. One big recipient is Brigham Young University. Mormons are the one group who bother to consistently learn foreign languages and serve in the armed forces. They are required by their religion, to do a one year "mission" overseas. So they get ample language training. This incidentally, is another aspect of our "policy" and our culture really; foreign language learning is primarily centered on military need (or in this case, religious zeal), not academic or personal edification. Having one group so overly represented in this domain should worry everyone. In addition, there is new interest in government on regional languages and dialects. Terrorists don't speak in Modern Standard Arabic. They speak in Tagalong, Pashto, Hausa, etc. The more obscure the language or dialect, the more interest there is. Linguists are the next big thing. And frankly, we don't have that many Hausa speakers available to us now. That said, you can see that here, there is a coherent policy to achieve a goal.
As for "minority languages" we have taken the tact that resources be made available to people as a service, but that English is the dominate language. We have tacitly accepted that it is more important that people have knowledge than English. I'd rather you know the laws of the road because you read them in Spanish that no knowledge at all and that you cause accidents. We never paid much attention to the fate of Native American Languages or the loss of Hawaiian languages. (Actually, an interesting study would be to compare the development of policies to protect endangered species with developing policies to protect endangered languages.) That was a fringe issue for bleeding heart- multiculturalists. There have been debates about Ebonics, studies done on how the non-standard dialect of many African Americans (i.e. poor English) prevents them from getting loans, jobs, building permits, voting ballots, etc. But these never forced any real, grounded policy formation except in one place: bilingual education. And that has been limited to southern border states (CA, TX, AZ, NM, etc) and those places like New York and Boston that have huge immigrant populations. And even then, the policies have been more experimental than fixed. We are still arguing over bilingual education with studies providing ammunition for both sides of the debate.
So that gives you some idea of the width and breadth of language policy and its implications. For the U.S, adopting an "official language" is the very tip of a huge iceberg.