I'm going to have to be short because I have a lot of homework due:
The Thomas and Collier article seemed extremely low on details to me, although it might have been a nice summary for folks who don't require a more convincing set of data. I found it interesting that Thomas and Collier were accused in some circles of generating a rather disappointing study in terms of scientific and analytical rigor (per Crawford's article). Even just looking at this short article, their data looks kind of made up and is rather unconvincing (which is not to say that it is wrong or actually fraudulent...).
The main Crawford article, on the other hand, was by far the most convincing argument in favor of extended bilingual education that I have read so far. It addresses a variety of sources of data, and it even addressed some of the arguments made by the immersion model supporters. I'm sure some readers might have found it to be too much data, but I really liked it.
I'm not sure that the data Crawford sites is completely irrefutable,
but as of this moment it is now my opinion that longer term bilingual
education is the most
effective format for ELL students - if it can be provided. This
is a big shift for me because up to this point I was withholding
judgment until I saw better data.
The only minor quibble that I might have with Crawford's article is
the broad categorization that the different ethnographic groups
performed differently in immersion programs strictly due to
socioeconomic factors. That could be the case, but I think the
jury is still definitely out on that one.
Now that the question of educational effectiveness has been addressed in the analysis of various studies, there is still the political reality to be considered.
I think there is a natural tendency among people of all nations to want to propagate a culture that "looks like them." Also, I think there is a prevailing attitude in America that immigrants are welcome to come (under certain conditions), but only if they want to come in order to "be American" (and the existing majority have come to think that Americans are English speakers who look and act a certain way). Given this perception, if Americans feel that immigrants are only here for economic reasons (and not to take on our ways), I think it makes some people feel that their country is being subverted - that the opportunities of American jobs, houses, whatever, is being taken from them without the immigrants properly "joining the team."
I say this not as a supporter of that position, but because I think it is important to really understand a viewpoint if you want to change it. It is not productive to stereotype a position as "they just hate brown people" (although I'm sure this is the case for some opponents of multi-culturalism). Changing people's minds on these issues is going to take a lot of work. There is a very well established conservative infrastructure in place now (i.e., Fox Network and all the other outlets that repeat the current conservative outlook) which serves to maintain the current order, and I don't believe that the old tools of protest and writing to politicians is going to overcome this in the long run.
Here is my theory: Immigrants will finally establish some legitimacy in the American political domain when you see more popular programs on TV where immigrants are positive central characters. If you want to effect change, get a high rated TV program!
If I can ever get to be a better writer some day, maybe I can help.
: )