There is no way to measure their true numbers, but gay activists say that in many cases, these “unicorns” began life as Republicans first — driven by conservative upbringings, economic issues and libertarian principles. They often did not acknowledge their sexual orientation, even to themselves, until middle age…

At 18, she registered as a Republican, and though she briefly reconsidered her party affiliation when she came out, Ms. Smith voted for Mr. Romney, albeit reluctantly. Echoing the more than a dozen women interviewed for this article, Ms. Smith said that liberal lesbians reacted more negatively to her political views than conservatives do to her sexual orientation.

“Mention that you’re Christian or mention that you’re Republican and suddenly you just get vilified,” she said. “That may be one of the reasons for the lack of visibility of gay women in the Republican Party.”

Still, she said, “What good are gay rights if your country is falling apart?”