To put it another way, opponents of same-sex marriage say they must argue in favor of traditional marriage, not against gay people or gay rights. “It’s really a broader defense of marriage and a stronger marriage culture,” said Will Haun, 26, a lawyer and member of the Federalist Society.

In the highest-profile effort, the National Organization for Marriage is gearing up for a march on the National Mall on Tuesday, the day the Supreme Court is scheduled to hear arguments on California’s 2008 voter-approved ban on same-sex marriage…

The issue, proponents of traditional marriage say, is one of presentation.

“These Republicans who are jumping ship are doing so because we have no way of messaging,” said Ashley Pratte, 23, the executive director of Cornerstone Policy Research and Cornerstone Action, a New Hampshire group that focuses on social issues. “Do you want to tell your friends when you’re out with them on a Friday night that they can’t get married? No, you don’t want to have that discussion, but you want to have a healthy discussion.”