Peter Singer has written a rather meandering article explaining why he thinks homosexuality should be legal and thereby demonstrates how leftists are doubly wrong. After rather a lot of pointless rhetoric:
If a form of sexual activity brings satisfaction to those who take part in it, and harms no one, what can be immoral about it?
The underlying problem with prohibiting homosexual acts, then, is not that the state is using the law to enforce private morality. It is that the law is based on the mistaken view that homosexuality is immoral.
The only interesting bit of this essay is that Singer is forced to be intellectually honest and admit that leftism requires the state to enforce private morality. He clumsily sidesteps the interesting question of what that morality should be, but by conceding that the battle to be fought is a moral one he undermines just about every leftist politician in America.