Together, that's over 90 million people. If all three (not to mention numerous other smaller religious denominations that believe the homosexual lifestyle is morally wrong) issued clear, unambiguous statements "recommending" that they DON'T want their churches to be involved in the BSA anymore, it would have a HUGE impact in America. The Catholic and Mormons could actually enforce such a directive if they wished (although I don't think that it's necessary to force their churches to comply), and if SBC may have absolutely no power on paper to do so, but we all know they could “strongly pressure” affiliated churches to do so if they wished (to the point where they'd be “uncomfortable” going to an SBC meeting if their parish had a Boy Scout pack it was sponsoring).
Unfortunately, NONE of these church organizations is willing to take that step. The Mormons have flat out said they will continue to support the BSA, and the Catholics and Southern Baptists have issued national statements saying they dislike the BSA’s new policy, but its OK for their churches and families to continue sponsoring BSA troops if they wish. (In both cases, you do have examples of individual Catholic and Southern Baptist pastors — assuming the SBA uses the title “pastor” — choosing to sever ties with their local BSA troop because of the new policy).
Bottom line, liberals know they can continue to get away with the continual moral decline in this country, and destroying the traditional American family, because most major church organizations will allow it.
No they couldn't and Baptists don't have parishes. Most churches don't even send a representative to the national convention and I doubt half the regular attending members could name the head of the SBC, or even the director of their local association. SBC churches just don't work that way.
Oh, and Cub Scouts have packs, Boy Scouts have troops.