Freedom to marry and freedom of religion have a lot in common

On some earlier posts regarding gay marriage, discussion has often come to an impasse because I think homosexuality isn't a choice and some people think it is. People are entitled to their opinions just as much as I am.

Basically, because some people think that homosexuality is a choice and race isn't, marriage equality doesn't fall under the same guidelines as the previous ruling of Loving v. Virginia that said banning interracial marriage is unconstitutional. For the sake of argument, let's say that homosexuality is a choice and gay people everywhere are simply choosing to be queer.

The United States Constitution protects certain inalienable rights, many of those which we are unable to determine (race, age, disability). However, the Constitution also protects rights which we do choose. According to the First Amendment, I can choose to worship anything I want and the government protects my right to do so. The Framers included rights for things unable to change and those that could.

To those who say that sexual orientation is a choice, I want to know this:

In light of fact that some inalienable rights we're able to choose, how can you still deny marriage equality on a Constitutional level? Take into account the changing/unchanging nature of the protected rights of race and religion and the decisions of the Supreme Court to grant marriage as an inalienable right when answering.

I'm interested to see what people have to say. I have some thoughts on the issue, but I want to start some dialogue first.