Well, I will admit that the argument of "de facto coercion" is not necessarily the most compelling one (the establishment clause argument has always seemed better to me), although I don't see anything particularly unsound with the underlying logic: if de jure coercion was prohibited by Barnette, then it stands to reason that de facto coercion is also prohibited. The situation is perhaps analagous to Plessy: "separate but equal" may be equal de jure, but not equal de facto. Similarly, there may be no coercion by law, but there may be coercion in fact.
Thus, the only question is as to whether there is indeed de facto coercion, and that is of course a debatable point.
Up till now, I have been very favorably impressed by your understanding of the constitution.
The establishment clause was explicity created to prevent an ESTABLISHED chuch (the Church of England is an ESTABLISHED church, as at the time the Roman Catholic Church was the ESTABLISHED church in many countries, the Eastern Orthodox Church in yet others).
There is a difference between nondenominational references (such as 'under god' and making a specific denomination the official church).
