I think it's very important that we know WHY Chief Justice Rehnquist and the Supreme Court ruled in favor of the BSA. I will address that quickly in this post. It has nothing to do with the ridiculous assertions in this forum.
Anyways, to summate:
The U.S. Congress chartered Boy Scouts of America in 1916, with the declared purpose of promoting "the ability of boys to do things for themselves and others, to train them in scoutcraft, and to teach them patriotism, courage, self-reliance, and kindred virtues."
Scout Oath "On my honor I will do my best To do my duty to God and my country and to obey the Scout Law; To help other people at all times; To keep myself physically strong, mentally awake, and morally straight.
The First Amendment does not prohibit practices, which by any realistic measure, create none of the dangers which it is designed to prevent and which do not so directly or substantially involve the state in religious exercises or in the favoring of religion as to have meaningful and practical impact. It is of course true that great consequences can grow from small beginnings, but the measure of constitutional adjudication is the ability and willingness to distinguish between real threat and mere shadow.
For the Boy Scouts to include "God" in their Pledge in no way defines them as a religion or a religious organization. Certainly not monotheistic. Rather, as Justice Stewart said in regards to a strikingly similar Pledge, an indication that we as a society "presuppose a Supreme Being".
Although in 1962 (Engel v Vitale) the Court ruled that "government . . . should stay out of the business of writing or sanctioning official prayers and leave that purely religious function to the people themselves," the Court explained,
"...There is of course nothing in the decision reached here that is inconsistent with the fact that school children and others are officially encouraged to express love for our country by reciting historical documents such as the Declaration of Independence which contain references to the Deity or by singing officially espoused anthems which include the composer's professions of faith in a Supreme Being, or with the fact that there are many manifestations in our public life of belief in God.
The Establishment Clause, then, viewed through the eyes of Court precedents, is to keep the government out of religion and leave religion to the people. They aren't to sponsor it, in other words, financially or otherwise. Justice O'Connor established the Endorsement Test.
http://www.fac.org/rel_liberty/establishment/index.aspx
The Establishment Clause prohibits government from making adherence to a religion relevant in any way to a person's standing in the political community. Her (Justice O'Connor's) fundamental concern was whether the particular government action conveys a message to non-adherents that they are outsiders, not full members of the political community, and an accompanying message to adherents that they are insiders, favored members of the political community.
On June 28, 2000, Chief Justice Rehnquist of the Supreme Court ruled that the BSA was a private, not-for-profit organization [where membership is a privilege, not a right] with the Constitutional Right of Expressive Association. Just because they deny admission based on sexual orientation does not make them a religion. Just because they require a pledge like this:
On my honor I will do my best to do my duty to God and my country and to obey the Scout law
does not make them a religion. As a matter of fact, that pledge sounds strikingly like the Pledge of Allegiance that the Supreme Court consistently upholds.
Therefore, it is in my opinion that based upon these quotes provided, the Supreme Court will be placed in a difficult position. A veritable can of worms. If they declare the BSA to be accountable under the Establishment Clause as suggested here, thus not eligible for government handouts, they have to a) establish that BSA is a religion, even though the precedent has already been set; and b) measure all instances that use the word "God" in like manner with the same measure, or Endorsement Test.
In 1989, Justice Kennedy provided many examples of official acknowledgements of religion that would be unconstitutional under the endorsement test (proposed by Justice O'Connor) including Congress' decision to add "under God" to the Pledge of Allegiance.
If you want to argue this broad an interpretation of separation of Church and State, then you must include the Pledge of Allegiance. However, the Court has time and time again stood in defence of the Pledge, even when it has struck prayers down that have stood by it's side in ceremony, such as the Graduation Prayer. The only time the Pledge was successfully argued against, it was ordered out of schools in the 9th District by the 9th District United States Appeals Courts. The Pledge is currently before the Supreme Court, but the Senators are in the midst of passing a bill to prevent lower courts from hearing such cases as being violations of the First Amendment.
My guess is the ruling gets overturned.