I am frustrated about this too. But, realistically, I believe that if the Republicans do not take the White House in 2016, the judiciary will be stacked with left-wing activists who will likely strike down all the progress we've made at the state level such as late-term abortion bans.
I have done all I can at the grassroots level with trying to get establishment Republicans to understand that moderatism does not equal electability. But the reason why I will vote Republican in 2016 even if I can't stand the candidate, lies with the courts if we are to have any chance of watering down or hopefully overturning Roe. I attend the March for Life in San Francisco in January, and most of the pro-life activists I have seen are millennials and minorities!
As for same-sex marriage, the activists and the media have successfully demonized the opposition to the point where the best we can hope for is the Supreme Court allowing the states to define marriage. If this doesn't happen, my hope is that the downright viciousness directed at places like Memories Pizza, Chick fil A, Christian orgs etc. will cause some to rethink.
Keep the faith and hang in there.