Primary electorates are invariably smaller and more ideologically extreme (for both parties) than are parties as a whole. Moreover, nominations are won by winning support of party elites -- activists, campaign professionals, party-aligned interest groups, party politicians. Opinions tend to flow down from those most active to the somewhat larger primary electorates. And as far as I can see, there are no changes either within the groups and leaders that make up the GOP, or in the opinions of those groups and leaders. So within the Republican nomination fight, opposition to same-sex marriage is still going to be a must-adopt position.