We would need an entire new court system and statutes in every state to handle divorces, paternity, inheritance, property settlements, etc. And new tax codes to address every deviation and grouping of human beings into "marriages".
How much will taxes be raised to pay for that?
Not much
Polygamy would still be extremely rare. You would not have a rush of people seeking to embrace it. You are basicaly moving someone from the single column to the married column. Divorces are always messy no matter what you do
Beyond the "yuk" factor, I see polygamy as none of my business and it does no harm
Tom is "married" to Louise, Mary, Jenny, and Joan. together the 5 of them have 10 kids, 4 cars, and a large house.
Louise and Mary decide that they are really lesbians and decide to divorce the rest of them. 2 of the kids have tom and louise as biological parents and 1 has mary and tom as biological parents.
One of the cars was given to the family by Louise's parents.
Tom has a business that earns 200K per year.
Louise was married to tom for 10 years, Mary and Jenny for 8 and 7, and Joan for 4.
Please describe the property settlement, child care arrangements, and alimony after the divorce.