As of May, 57 percent of Americans favored same-sex marriage — but 72 percent said that marriage equality was inevitable, according to polling by the Pew Research Center. The inevitable arrived Friday, as widely expected, when the Supreme Court issued a ruling establishing that same-sex couples have the right to marry throughout the nation.

While support for gay marriage has been on the rise nationwide for the last decade, groups that still oppose it tend to be white, older, Republican, more religious, and, moreover, tend to live in states that hadn’t legalized it already. So although at the national level it appears that opponents of marriage equality are fading into irrelevance, in constituencies where conservatives hold court, the struggle against progress rages on — and that means candidates must be seen resisting and challenging the ruling. And “religious liberty” is proving itself to be a useful weapon in the fight.

Using what Rolling Stone describes as a “simple semantic trick of calling” gay marriage “a religious liberty issue,” conservatives can conveniently avoid the kind of explicit discriminatory language that divides people, while letting voters know where they stand on the issue. Consider Louisiana governor and Republican presidential candidate Bobby Jindal. The tweets he posted in the wake of Friday’s ruling mentioned “religious liberty” twice, and he said in a statement: “This decision will pave the way for an all-out assault against the religious freedom rights of Christians who disagree with this decision. This ruling must not be used as pretext by Washington to erode our right to religious liberty.” (“Religious liberty” is also the name and focus of his first campaign ad.)

“Religious liberty” is used as a catch-all for opting out of legislative acts and judicial rulings that favor progressive policies that conservatives don’t like. It’s a term they can rally behind as way to protect what they characterize as a way of life and a set of values. Those fighting under the “religious liberty” banner want to extend religious protections outside the realm of religious institutions (like churches) and into normally secular contexts. By tying it to economic and business concerns, they can pick up constituents who care about dollars and cents, rather than making it about a culture war they’ve already lost.

Jindal, for one, likens any restrictions of “religious liberty” to regulation and other allegedly “anti-business” practices: “Those who believe in freedom must stick together: If it’s not freedom for all, it’s not freedom at all.”

In former Arkansas governor and Republican presidential candidate Mike Huckabee’s statement Friday, he alludes to cases where businesses were fined for not supporting same-sex couples.

That’s what’s to expect in the next round of the marriage-equality battle — same-sex rights vs. the rights of those with religious objections.

Even Justice Anthony Kennedy, in his majority opinion, said that “religious liberty” challenges are acceptable: “It must be emphasized that religions, and those who adhere to religious doctrines, may continue to advocate with utmost, sincere conviction that, by divine precepts, same-sex marriage should not be condoned,” Kennedy wrote.

Activists are pointing out that even with today’s ruling, the fight isn’t over: There are 28 states that don’t provide protections against discrimination in the workplace, housing, or in public accommodations for LGBT people, despite many beliefs to the contrary.

Many non-conservatives see this “religious liberty” fight as a last-ditch attempt against something that has largely been decided already, “a way for religious conservatives to negotiate surrender,” as Ross Douthat phrased it.

Not all Republican presidential candidates who have come out against today’s ruling mentioned “religious liberty. “States’ rights” — the old standby that New Jersey governor Christ Christie and Florida governor Jeb Bush cited in their objections to the ruling — has a history of being aligned with conservative and sometimes questionable stances. It has often been invoked when referring to the legacy of the Civil War.

The conventional wisdom is that the fire-and-brimstone rhetoric is good for firing up the base and could work to Republicans’ advantage in the primaries. But now that the issue of marriage equality is seemingly settled, will most Americans care enough about “religious liberty” to vote Republicans into office?

Photo: “Religious liberty” is not just about practicing religion freely. For many, it’s about having the right to refuse to provide goods or services that are against their religious beliefs. That’s the line of attack Republicans are expected to use on LGBT issues now that the marriage question has been settled by the Supreme Court. American Life League via Flickr