Welcome to the exciting new world of the slippery slope. With the Supreme Court’s landmark ruling this Friday legalizing same sex marriage in all 50 states, social liberalism has achieved one of its central goals. A right seemingly unthinkable two decades ago has now been broadly applied to a whole new class of citizens. Following on the rejection of interracial marriage bans in the 20th Century, the Supreme Court decision clearly shows that marriage should be a broadly applicable right—one that forces the government to recognize, as Friday’s decision said, a private couple’s “love, fidelity, devotion, sacrifice and family.” The...