I think we're going to disagree about polygamy, so I'll leave that aside because its really a whole other thread on its own. I'll just say this - gay people pushed for marriage equality, and that's why progress is finally happening. If other groups want the same, they have to do the same.
I'm not talking about polygamy of the Mormon/Muslim/Creepy Cult kind. Lots of creepy religious freaks are monogamous too. I'm talking about polyamory for those who are informed, consenting adults. Why are they relegated to being without these rights?
Not all gay people pushed for marriage. Over the years, I've known lots who really really couldn't care either way.
The ones who pushed for marriage are the more conservative gay people, generally.
But I'll say it again: EQUALITY IS GOOD. I'm not against that. So let's argue about why the state needs to be involved in ANYONE's marriage.
When you have a lovely romantic thing between two lovers which goes south, how does the fall out get decided fairly? Does the bigger guy just beat the crap out of his woman and boot her out the door with the clothes on her back? Does the woman manipulate the children into hating their father so she gets child custody?
I realise those are extreme scenarios, but they are the type of scenarios that an impartial judge is there to prevent.
Well you're answering your own question there. Extreme situations. Anyway, I don't mind having the state as an option, like I said above, the way religion is now. For those who want to have a contract with the state (like people do with their churches, etc.) should have that option IMO.