In 1992, Bruce Herschensohn, an intellectual who is a solid conservative was running for a US Senate seat from California against Barbara Boxer. The Friday before Election Day, a report came out that Herschensohn was spotted at strip joints.
The timing of the story was suspect, and even if it was true it should not have made much of a difference-- Herschensohn had never raised moral issues of the sort in his campaign. But some "Christian conservatives" who called in to talk shows over the weekend ate it up and said they wouldn't vote for him because they now saw his alleged behavior as un-Christian, or something like that.
Barbara Boxer went on to narrowly win the election. And I assume the "Christian conservatives" who couldn't vote for a "sinner" like Bruce were happy with the result.
Right, in a number of these cases it is about convincing the GOP base to stay home.
They cannot compete in the arena of ideas and get people to vote for their policies. They have to lie about things like opposing same sex marriage and then after the elections claim they evolved on the issues.