A key point for me is, as Mark Holmes posted early in the discussion, marriage rights are a life-changing, crucial matter for gay couples, and a preference (whether strong or weak) for the rest of us. One can oppose gay marriage, but stop well short of amending a constitution to ban it. To do otherwise is to hazard democracy becoming the proverbial two wolves and a sheep voting on what to have for dinner.
(Personally, I think initiative constitutional amendments are a travesty for exactly this reason)
