>>>>If marriage is a fundamental right as opposed to a privilege I can see this argument coming up in the future based on the 1st and 14th amendments.
>>>>
>>>>>Why don't we ever see one woman marrying many men?
>>>
>>>Marriage is a religious entity, so I can see how an athiest or agnostic might think it's okay to marry a ______________. (fill in here)
>>
>>It may have started out as a religious ceremony, but as it stands right now, "marriage" is a legally defined institution with benefits and responsibilities provided by the state. Take a gander at your marriage license if you disagree.
>>http://www.usmarriagelaws.com/search/united_states/tennessee/index.shtml
>
>If marriage doesn't have a religious underpinning, then why can't people marry multiple wives, or vice versa? The only reason is a moral reason, and last I checked, the "state" is amoral (and how).

Multiple religions advocate polygamy. The laws of the "amoral" state prevent the practice in America.