I cannot oppose the personal choice to marry more than one person.
Migrendal-
You have said in another thread that you oppose cultural practices that encourage women to stay at home to care for children.
But don't you think that most exisiting cultures that sanction polygamy are oppressive to women to an even greater extent (e.g. fundamentalist Mormon and Muslim communities)?
I would go so far as to say that polygamy, like pedopilia, is inherently oppressive, at least in the forms that it is seen in real life.
I don't think polygamy is comparable to gay marriage, where the same concerns about oppression don't exist.