But is 'marriage' political? Is it religious? Is it technically a violation of The Constitution of The United States to officially recognize it if it is a religious union? The defense of marriage crowd is pushing for a showdown on this that they are going to lose because we know the answer to the latter two questions is yes.
I would suggest that marriage constitutes a civil union, and the Supreme Court will likely end up making the same connection, rendering argument one way or the other moot - and specifically avoiding a declaration of marriage as a religious institution to avoid the unwanted quagmire that would create.
The courts are saying that a justice of the peace or other government agencies that can perform legal unions of two people can't prevent that union based on gender.
No one is saying, or ever said, that the widely accepted "mainstream" religions have to perform ceremonies for those that do not ascribe to that religion's tenets. If a church's definition of a union requires one from each gender, then those are their rules. Don't like 'em? Go to city hall.
The church is a substitute acting on behalf of the state to perform the ceremony. The state issues marriage licenses, the state may require blood tests, the state may require infectious disease tests before allowing any legal union. What's the big deal with having the state complete the work they start?