And, as I've pointed out before, the only reason secular liberals who support gay marriage now have to also say they wouldn't be opposed to things such as polygamy is so they don't appear inconsistent. Guaranteed, if gay marriage was not an issue, those liberals (including the ones on this board) would come out with all sorts of arguments against legalizing polygamy; despite the freedom of religion grounds for it. But they know they can't do that now. So it really isn't about "equal protection under the law" for them. It never was. Like the judges and lawyers who have supported this, they simply twist the Constitution to suit their own agenda.
The polygamy argument with respect to marriage equality holds no water for a couple of reasons, which have been stated before.
First, the civil institution of marriage recognizes hundreds of legal rights, responsibilities, benefits and obligations that would be frustrated and compromised by recognizing polygamous unions as legally valid. On several occasions I've posted examples of these and don't feel like answering the same question repeatedly. But the marital policy objectives of proprietary rights, joint tax returns, property rights on dissolution of marriage (equitable distribution), Social Security and Medicare (especially for the possibility of long term care, parenting and adoption rights, as well as insurance, pensions, duties of child support and debts of spouses are not achieved by polygamous relationships.
Secondly, there is a huge distinction between the would-be polygamist, who wants several spouses, and the homosexual, who wants one. The polygamist can enter into and receive all legal and financial benefits that legal marriage offers. There is no due process or equal protection argument of merit as he can fulfill the requirement of marriage. The gay person, unlike the polygamist, is barred from the benefits of marriage at the very beginning. Therefore, the Fourteenth Amendment arguments are available to him.
Also, your argument that the polygamist has a stronger argument for state/legal recognition of his plurality of marriages is ludicrous and underscores a fundamental ignorance of constitutional principles. The state is not required to recognize or validate unions performed by churches. According to the state the marriage is recognized by a civil license. It is not the obligation of the state or judiciary to conform public policy about marriage to include religious views on the topic. Religions are free to perform their wedding rituals, based on dogma, creed or mythology. If a church wants to let a guy marry ten brides, knock yourself out, but the first bride to get the license at the court house is the only one that the state should recognize as a legal wife.
