Noun-Tolerance and Verb-Tolerance
In the last third of the 20th century, there were two movements for more tolerance. One of them was for more tolerance of minority groups (we can call this “noun-tolerance”) and the other was for more tolerance of previously deviant actions (we can call this “verb-tolerance”). In recent years, more people have realized that verb-tolerance produced epidemics of crime, abortion, illegitimacy, and divorce. On the other hand, noun-tolerance is widely regarded as a step forward.
The remaining advocates of verb-tolerance are trying to blur the boundary between the two types of tolerance and use the continuing loyalty to noun-tolerance as a lever. For a while, they tried accusing anybody opposed to verb-tolerance of being a racist/sexist/classist/whateverist bigot. When President Bush came out in favor of relaxing immigration laws, they realized they couldn't get away with that and switched to gay rights. On the one hand, gay rights can be considered a form of noun-tolerance (tolerance of gay persons). On the other hand, gay rights can be considered a form of verb-tolerance (tolerance of homosexual activity). Since other forms of gay rights have attracted less opposition than expected, they invented gay marriage in an effort to make consevatives continue to look bigoted. If more conservatives back gay marriage, they'll come up with something else. (I am not imaginative enough to figure out what that will be.)