If the UU's (as an example) have decreed that they recognize and celebrate same-sex marriage, how is it not violating religious freedom for a state to force them to NOT perform said marriages? What's good for the goose is good for the gander.
Yeah, that's a point that doesn't exactly get represented in the larger dialogue, and a pretty good one. Kinda' cuts to the point that the advocates against same sex marriage aren't doing it for religious freedom, they're (at best) doing it for their religion's "freedom." It's nice to see some folks getting some attention fighting for religious freedom writ large.
Well, and let's make clear that what they (the anti-SSM advocates) are fighting for is
their religion's freedom to discriminate. Which has typically not been recognized as a valid right by most courts (although
Hosanna-Tabor Church v. Equal Employment Opportunity Commission certainly could be interpreted as allowing exemptions for religious institutions from things like equal opportunity labor laws).
It's a thorny issue: One the one hand, religions shouldn't be able to exempt themselves from civil protections and be legally able to create second-class citizenry. On the other hand, government should not be able to dictate to religions what parts of their doctrine they are allowed to practice.
In a perfect world, it would be left up to the market of ideas, and people would vote with their feet -- if the majority of individuals favored gay marriage, in theory they'd leave close-minded denominations and choose SSM-friendly ones. But it's nowhere near that simple. Most people can't "shop around" for a new church the way you can for a new car.