Republicans hate identity politics. They're not supposed to care if you're LGBT or Black or Latino. They're supposed to care who's best for the job, regardless of anything else. Of course, Republicans do care, because every LGBT or Black or Latino elected official is proof that the party isn't homophobic or racist or xenophobic and that anyone can vote for us. DeMaio, to his credit, isn't running as "Hey, I'm a gay Republican. Vote for me." He's making this about fiscal issues. So maybe, eventually, the media will get tired of "Hey, I'm a gay Republican." stories and recognize that DeMaio is just a strong Republican challenger.
I do have a quibble with the article. Libertarians aren't socially liberal. They are socially libertarian. They may have the same basic stance of some issues, but the difference is that libertarians believe gay marriage is okay because hey don't want government meddling with marriage, while liberals believe government should be enforcing "marriage equality."