Heterosexuals may not marry someone of the same sex either. Therefore, the law is not homophobic. It is the same for all.
That reasoning hasn’t been persuasive to courts. That kind of thinking would mean that laws prohibiting interracial marriage are constitutional and nondiscriminatory, because both white and black people can’t marry people of the other race.
The more coherent and persuasive argument is that insofar as there’s a fundamental constitutional right to marry that would be violated by anti-ssm laws, the right is limited to how the right would have been understood at either the founding or at the time of the 14th amendment - i.e. to opposite-sex couples only.
Also NO State demands you prove you are a heterosexual or in Love to get married. There are only three simple rules. 1. No close family members. 2. No one too young. 3. Not the same sex. How are any of these things discriminator? They are just common sense on how to maintain a stable family.
And even simpler than that — there is no “right” to marry at all. Legally, marriage is nothing more than a contract.
So if Washington State someday bans straight marriage and allows only gay marriage, that will be constitutional?