The Supreme Court has yet to announce its ruling on the legality of same-sex marriage, but most Americans predict that by July, gay and lesbian couples will be able to wed in any state in the union. The PRRI Religion & Politics Tracking poll finds that nearly two-thirds (65 percent) of the public, including roughly six in ten (58 percent) Republicans, believe the Supreme Court will legalize same-sex marriage in all 50 states by overturning state constitutional bans.

With a majority (55 percent) of Americans now in favor of same-sex marriage, such a ruling would be welcome result to most of the public. However, findings from the American Values Atlas show that Republican opposition remains robust, even in the face of dramatic shifts in public opinion: 58 percent of Republicans oppose legalizing same-sex marriage, while roughly one-third (35 percent) say it should be legal.

In the face of a rapidly changing public opinion and legal context, are Republicans likely to make an abrupt about-face on the issue? It’s doubtful.

First, although Republicans are facing their own internal generational schism on the issue, young Republicans (age 18-29) are not nearly as supportive as young adults overall. A majority (53 percent) of young Republicans favor same-sex marriage, while 42 percent oppose. A majority of Republicans in every other age group, including seven in ten (70 percent) seniors, oppose same-sex marriage.

The modern-day GOP is a conservative party—nearly seven in ten (68 percent) identify as politically “conservative”—and conservative Republicans strongly oppose same-sex marriage. Two-thirds (67 percent) oppose legalizing same-sex marriage. And while a majority of moderate (55 percent) and liberal Republicans (55 percent) favor allowing gay and lesbian couples to marry legally, these two groups account for less than one-third of all self-identified Republicans combined.

Among Americans overall, higher education is linked to greater support for same-sex marriage, but this pattern is not found among Republicans. Republicans with post-graduate degrees oppose same-sex marriage nearly at about the same rate as those with a high school education or less (58 percent vs. 63 percent, respectively).

Finally, no religious group exerts greater influence over the politics of the GOP today than white evangelical Protestants. More than one in three (36 percent) Republicans identify as white evangelical Protestant and no religious group expresses greater antipathy to same-sex marriage. Nearly eight in ten (79 percent) white evangelical Protestant Republicans oppose same-sex marriage, including roughly half (49 percent) who report that they strongly oppose it.

Over the last decade, Republicans have become somewhat more supportive of same-sex marriage, but the attitude shift is far less dramatic than that seen among independents and Democrats. In the absence of a major electoral or political shock, it’s hard to see the GOP embrace same-sex marriage in the near future.

For more public opinion on same-sex marriage, see PRRI’s “Everything You Need to Know about Same-sex Marriage for the Upcoming SCOTUS Case.”