I know that there are several poly- words, including polyamory and polygamy, but am not knowledge about the distinctions. I thought polyamory was a catch-all word for "romantic relationships where people can have more than one partner, with the knowledge and approval of all other partners." Or something to that effect. And polygamy is a particular kind of polyamory where the partners are married. I could definitely be mistaken about those words' meanings, though.

Since poly was brought up by the OP in the context of gay marriage and civil unions, I used polygamy. But I certainly didn't mean to imply any sort of connotation by the use of "polygamy" rather than "polyamory."