I think I'm for legalizing all. Read the book _Under_The_Banner_Of_Heaven by Jon Krakauer. It's about FLDS compounds throughout North America. It's never going to be enforceable - but I think getting it out in the open may prevent, to some degree, the child marriages that seem to occur frequently.
As far as tax-breaks go...I think all tax breaks for marriage (monogamous, polygamous, and whatever else there is) should be repealed. Tax adults on an individual basis by income - get rid of tax breaks for children (never understood this as they are a tax-burden but I guess the State wants a growing demographic). I don't see the problem with any kinds of marriage then. Let banks, and other companies that have specific rules for joint accounts, or co-signers or what have you, deal with the rest.







