Barro studies the right-wing media’s response to Murkowski announcing that she supports marriage equality:

Nothing at National Review, the Weekly Standard, Human Events, the Washington Free Beacon, or the American Spectator. Breitbart.com ran two Associated Press stories. WorldNetDaily ran an NBC News story. The Daily Caller and RedState mentioned Murkowski in pieces about immigration reform, but nothing on gay marriage.

The only conservative outlet I found covering Murkowski was the Washington Examiner, which ran a straightforward news story about her announcement.

Four years ago, it was hard to imagine Republican senators supporting gay marriage. It was even harder to imagine conservative media outlets having no reaction at all to them doing so.

He believes that “the national conservative media is done with engaging on the issue.” Timothy Kincaid likewise notes how the debate over marriage has shifted:

[I]t seems to me that we have entered a phase in which one can be “not ready” or “not convinced” or “not yet evolved” on the issue of marriage equality. That’s simply opinion. But to be actively opposed suggests a character flaw, something with a whiff of nastiness and maybe even vile. The public – right and left – seem to have decided that you can support gay marriage or you can not support gay marriage, but you can’t oppose gay marriage any longer.

So more and more, those who can safely be assumed to favor heterosexual superiority simply choose to say nothing. Instead of defending their God-given moral view, they announce their support for states’ rights, defer to the wisdom of the courts, or just change the subject.