An excellent suggestion from John Holbo:

Now the striking thing about 'politically correct' is that it really means the same as 'moral values', as per Republican rhetoric and post-election polls, etc. Both terms denote sets of moral beliefs which are held strongly enough that believers are prepared to impose them on others, politically. Obviously the sets in question are different, but the thing that makes the term toxic to the bearer is actually the connotation. The elitist moral superiority of it. So what we need is an appropriate analog to pin on conservatives. There ought to be one, by rights, since the Republicans surely are elitists, and they surely do think they are highly morally superior.

Once you put the problem that way, the solution is obvious. Let's get in the habit of calling Republican moral elitists: 'the moral elite', 'morally elite', 'moral elitists'. Just use the terms as flat descriptors for anyone proposing to legislate morality in any of the usual ways. Just to change things up, sometimes you use: 'morally superior' to designate the attitude. And 'moral superiors' to designate the tribe. Maybe you start to distinguish, as a matter of course, between legislation that ensures 'moral superiority' and the regular stuff. Talk about Repubicans taking 'necessary moral superiority measures'.

The beauty of it is that 'morally superior' is already a term of faint opprobrium. It connotes petty social snobbery, schoolmarmery, so forth. It stinks. And it fits. Perfect for our purposes. And 'moral superiors' sounds worse.

It should be hard for Republicans to unstick this stuff from themselves, if accurately applied, because what are they going to do: deny that they are morally superior? In the context of, say, proposing to legislate against gay marriage, can they deny that they think they are morally superior to those who think this stuff would be alright? If they deny they are morally superior, then what do they think they are doing? Letting your neighbor be is such a fundamental American value that it is very embarrassing to be on the wrong side of it, as Republican often are these days.

Elite is another good one. Republicans love to dish it out. They ought to get a taste of their own medicine. Again, the hook should be hard to weasel off. Suppose the target denies being 'a moral elite'. Then what proper business does this lot have bothering their neighbors with imposed 'moral values'? Only an elite should think it knows enough about right and wrong to take that rather extreme step. If they are not an elite, they are morally irresponsible.

There should be endless chances to needle people. 'Over at the Corner there is a lot of moral superiority blogging going on today ...' 'Senator, do you support this measure because you are morally superior?' Right now it sounds a little odd, these terms. That's why we have to start using them today. Break them in.

It’s worth a shot.