The constitution applies to all people living within the United States. Since marriage in not mentioned or even implied within the document, I don't see the connection the theocrats keep insisting exists. The constitution establishes an implied wall of separation between church and state, protecting all citizens from the myopic biased untenable views of theocrats. Saying some people can marry while others can’t is based on theocratic bias and has no place in the fair treatment of all people. For those of you who do not really know the constitution, Article VI states that no religious test shall ever be required as a qualification to any office or public trust under the United States. Also, oaths, for those believing in a deity, are given equal weight to affirmations, for those who do not. The First Amendment supports these statements in the body of the constitution all of which imply, without having to state exactly, that there is a separation of church and state in the United States.
Marriage by anyone to anyone else within our country is a personal and private matter and is not dictated in the constitution by theocratic dogma.
My faith is my business and I will not impose it on other people. Those of a different understanding, practice it on your own time not ours. There are many paths to understanding the Universe, mine, like yours, is not dependent on each other. Peace