Over the course of a noxious but in no way atypical rant about how minorities should have the moral grace to apologize for all the terrible things they have done to white people, Prager lets this one slip:
The absence of any expression of shame in the gay community over the current blacklisting -- and attempts to economically destroy -- anyone who donated to the California proposition defining marriage as between a man and a woman is another example.
To make this perfectly clear: what Dennis Prager is suggesting here is that gays should apologize for using perfectly legal means to oppose a movement that was attempting to deny them their basic civil rights under an already-existing law. (The "blacklisting" and "attempts to economically destroy" stuff is a particularly nice touch; what he's referring to is economic boycotts of Prop 8 supporters. Boycotts, when wielded by conservatives, are morally beautiful things, but when used by liberals to protect human rights, they're nothing less than economic terrorism.) What he is suggesting is that gays should be ashamed of their nonviolent attempts to preserve their basic legal protections.
But there's more to it than that: keep in mind that he wrote this column after Proposition 8 was passed, thus instituting a Constitutional amendment that stripped them of their extant right to marry. So Prager is essentially insisting that a defeated minority apologize to him for having dared to defend a freedom they fought intensely to gain in the first place. For all his highfalutin talk in the piece about "the highest expression of moral development", he is not only saying that gays should be ashamed of fighting peacefully for their rights, but now that they have lost those rights, they should come before those who took those rights away and say they were sorry. This is the talk of the slave master who believes it is "maturing" for his runaway servant, having been captured and dragged back to the plantation, to get down on his hands and knees and say that he's sorry he ran in the first place. That's how Dennis Prager sees the world functioning at its peak moral order.