[AnotherUnixGeek]

But what, exactly, is bad about it?

For one thing, males who wield power and influence will claim several wives, while males lacking such attributes will have to do without. Young males will often be forced out of communities to prevent any possibility that they will compete with the older, more established males. This phenomenon is seen in tribal cultures which practice polygamy, such as unreformed Mormon cults, Muslim societies and groups of chimpanzees.

What interest might the state have that would justify refusing recognition of such marriages?

Stability of society - large groups of young males unable to find mates are a recipe for social unrest and violence, as seen throughout the Muslim world today. This fact is known to Muslim terrorist groups, which reportedly rely on marriage to stabilize and calm down unwanted recruits and former members who might otherwise cause mischief unsanctioned by the terrorist groups.

[puroresu]

Yes. Polygamy was accepted in many ancient lands because it allowed for more women and children to live in an upscale environment. Liberals are too dense to grasp this, but for much of human history there was no social safety net, not to mention no concepts of human liberty, individual rights, and so forth.

Polygamy meant that a wealthy man could have multiple wives. These wives and their offspring ate better, got better medical care, had better clothing, than the wife & kids of some poor subsistence farmer scratching out a living on a tiny plot of rocky land.

Of course, this left many lower scale men unable to find mates at all. But the excess males were put to work building pyramids, rowing ships, fighting wars, and so forth.

Polygamy clearly does not fit into a society where people on the whole are well off, and where concepts of human liberty are important. Ditto for slavery. Many people project backwards on these issues and react with horror that the Greeks owned slaves. But slavery basically served the function of a social program, providing the rich with an incentive to care for at least some of the poor. If you owned a slave, it was in your best interest to feed him and keep him healthy.

This is why neither slavery nor polygamy are outright condemned in the Bible. But neither are they mandated. As our societies grew wealthier and as our understanding of human liberty grew stronger, we discarded these institutions as inappropriate for our Western Civilization. The fact that liberals are now talking about bringing polygamy back shows they have no historical understanding whatsoever, and are merely trying to destroy us and make life easier for our sworn enemy Islam. They'd bring back slavery, too, if they had a chance.