Yes you are denying liberty and equal protection unde rthe law, because certain rights and privleges come with marriage. For instance, tax breaks, and the right to make medical decisions for your spouse. If you deny same sex couples the right to marry under the law, you are denying the of those rights that hetero couples enjoy. That isn't equal, nor is it just.
If you define marriage at all, you exclude someone. Otherwise you wouldn't have to define it. Think about it.
It makes as much sense to you, because you are hetero. A gay person would tell you that having sex with a person of the opposite gender would seem about as sensical to him/her as banging a picinic table as well. Last I checked, you're not the arbiter of what is and isn't a legitimate relationship.
Sexually motivated behavior plays a critical role in the survival of dioecious species. It's not just a matter of preference. It's the role of sexually motivated behavior in biology. Prefering sexual contact with members of your own sex in the context of the role of sexually motivated behavior in biology makes about as much sense as preferring sexual contact with a picnic table does. That is not true of preferring sexual contact with members of the opposite sex.
this is your definition. If you were gay, you wouldn't think that way, and having sex with a member of your own gender would seem natural to you. The fact is that most gays are born that way. It's not a choice, so denying them rights and equal protection under the law is unamerican, and will be proven to be unconstitutional in time.
I don't think it will be "proven" unconstitutional but I do think there is a good chance that the Judiciary will once again pervert the Constitution and declare that there is some "equal protection" issue.
When I talk about what "sex" is, I am talking about the role that sex plays in biology. Is masturbating sex? Is gratifying yourself with a picinic table sex? It is according the the broad definition commonly used nowadays.
But, biologically and in our species, sex is the insertion of the male penis into the female vagina followed by the ejection of spermatazoa which hopefully fertilize ova. That is what sex is all about.
Well, admitedly there are many who hope that fertilzation does not take place. But that is the basis behind the drive. Saying that a homosexual sex drive is normal is like saying that a hunger drive directed towards eating sand is normal.