Yes, because we are all human beings just being differentiated by our genders. What matters is from the inside, not the outside. I'm very confident to say that homosexuality is a thing that should be accepted because what we people choose makes us happy. Although I do not know how homosexual people think, i could say that we are not different from them. We should accept them and treat them like how we treat other males and females.
In order for such an argument to be made, the burden of proof must be sated. The instigator has NOT given any evidence, nor do I see any, that gender confused citizens of America are being mistreated. I also would state that the concept of gender confusion is even a matter that 'rights' as defined by the constitution must address.
I would appreciate it if the instigator were to give any actual instances of the 'gender confused' having their rights taken or abused. Marriage isn't exactly a 'right' defined by the Constitution, nor is it necessary for the document to address it at all, marriage as we know it has only been around for a few centuries, therefor their's no necessity for the government to recognise WHO you're married to at all. The largest argument I've heard besides 'they're being wronged' is the statement that certain insurance companies don't give marital benefits to homosexual couples, and sure that should be changed, but no one discriminates against the 'gender confused' in a legal sense.