Wellll:
2015 WSJ/NBC poll
59% of all Americans support same sex marriage
40% of Republicans support same sex marriage
35% of conservatives support same sex marriage
29% of core Republican voters support same sex marriage
50% of Republican voters would be less favorable to a candidate who didn't support same sex marriage
19% would be more favorable
Support for Gay Marriage Hits All-Time High — WSJ/NBC News Poll - Washington Wire - WSJ
2014 Gallup
55% of all Americans in favor of same sex marriage
58% of independents in favor of same sex marriage
63% of moderates in favor of same sex marriage
Same-Sex Marriage Support Reaches New High at 55%
So yeah, tide is changing. Still think Republicans would do much better with younger voters if they eased way up on social issues. Highly doubt the "religious right," is going to bolt if they did. Who are they even going to vote for if they tried? Libertarians would probably be seen almost as bad as voting democrat, and not sure any of the smaller parties on the right even get on the ballot most of the time.