A new paper in Demography shows (in line with prior studies, e.g., here and here) that states that allow same-sex marriage do not, in fact, show reduced rates of opposite-sex marriage. This matters, presumably, because some opponents of marriage equality had predicted that allowing same-sex marriage would weaken the institution of marriage generally.
The thing is, though, does anyone really think that such findings will matter much to people otherwise opposed to same-sex marriage? For example, Jon Haidt’s work on intuitionism and moral dumbfounding makes the case that the expressed reasons people give for views on topics like same-sex marriage are often post-hoc rationalizations rather than the genuine motivations for opposition or support.
In reality, findings like those in the Demography article are part of an odd bit of policy theater, where one side provides an empirical argument (we oppose same-sex marriage because it will harm opposite-sex marriage) that the other side knows isn’t a real reason for their policy views, the other side goes about falsifying the claim anyway (pretending that they take the argument seriously), and the one side either ignores the finding or claims the finding is flawed or points to a competing study or simply moves on to some other post-hoc rationalization, without anyone’s policy judgments having changed.