An interesting article. I don't have time at the moment to check all his sources, but his thesis is not so dissimilar from my own.

For reasons that I am sure you will understand, my gravest concern is the entrenchment of a particular brand of faith in US Law. The ascendancy of any given orthodoxy - Be it a Focus-on-the-Family style of Christianity, or the rigid secularism that has led to the prohibition of religious dress in government spaces in France - runs counter to the intent of the establishment clause.