The Boy Scouts have their own legal advice that given the Supreme Court decision they are positioned on the wrong side of the Constitution (Equal Protection Clause, Due Process Clause) and rapidly growing public sentiment that views "gay" rights as a civil rights issue.No it isnt - its been upheld by the supreme court that a private membership club can discriminate.
The boy scouts head leadership chose to allow this now from within, they have won many lawsuits in the past and its been upheld that they could deny based on gay.
Keep in mind that this decision came from a conservative Supreme Court where 5 of its 9 justices were appointed by Republican presidents.