Same-sex marriage is not on the rocks — yet. But the LGBT triumphalism of a few years ago is receding. Support for same-sex relationships is dropping, businesses are less inclined to pay for “pride” festivities, and Republican leaders are reclaiming June from the rainbow. This wasn’t supposed to happen. The issue was supposed to be settled, with the rainbow triumphant and opposition receding to a few marginalized religious weirdos. But in the years since the Supreme Court invented a right to same-sex marriage in the Obergefell decision, the effects have become clear, and they aren’t what we were promised. Same-sex...