There are reasonable solutions to seemingly intractable social problems, such as same-sex marriage and the Boy Scouts’ exclusion of “gay” leaders. All persons, particularly Americans, enjoy constitutional rights of association. We can associate with like-minded persons without demeaning or antagonizing others.
Marriage, since time immemorial in all nations and religions, has been universally understood to be the union between one woman and one man. If some prefer to deviate from this venerable definition, they can define their different relationship (civil union, for example) without usurping the name “marriage” as their own. This solution should reasonably satisfy both sides.
Similarly, if some don’t want to associate with the Boy Scouts, they can form a different association with their own rules (Young Pioneers, for example). Both could join whichever association they preferred without demeaning or antagonizing the other. Forcing persons to accept their associates is un-American. No “authority” can force me to join one or the other. Only in China or Iran can this abuse happen.