Although that's probably the response, the mere attempt to justify deviates being allowed to join would be damaged significantly by public perception, and the court would be faced with the battle of competing expert witnesses arguing the point, ad nauseum, and coming to some compromise that would be SHORT of forcing cut-off's of public funding of the Boy Scouts, I believe. (depends if it gets past the the 9th Circus Court of Appeals, which surely would be where the ACLU would bring the case to get to the 9th Circus).
I would hope so but some in "the public" worry me. I truly hope the BSA finds a slick "gotcha" lawyer.