You will find that the Bible, if you want it to, will justify many things. St. Paul had a very male chauvinistic view of women. He would say things like women must not talk in church, must cover their heads, they mustn't talk and must remember that it was a woman who first tempted and this whole mess started because women messed us up. So you can read it in such a way that it justifies polygamy.
Desmond Tutu