Wingnut- “Homosexuals are filthy sodomites who should not have access to marriage.”
Evil gay person- “Nonsense. I demand the same rights as you and will fight for them.”
Wingnut- “Why won’t you respect my right to free speech?”
And there you have the wingnut understanding of the Constitution.
See, there's the problem. Free speech is one thing. You're free to say that you don't want me to get married. However, when you use the law to try to enforce your viewpoint at my expense, then I get upset and start to fight back using whatever means are at my disposal.
A similar argument might go like this:
Communist: I believe that capitalists are filthy pigs who should not have access to private property.
Capitalist: Nonsense. I believe in private property and I will fight for it.
Communist: Why won't you respect my right to free speech?
See, the Communist has the right to say that he doesn't believe in private property. However, when he uses the law to try to deprive you of your private property, then you have the right to fight back.
That's the difference.
See it now?