Yep. I'd say it was a cheap shot.
The ultimate cheap shot, tucked away in an article about "compassion."
Cheap shots
Lying
Stereotyping
Stereotyping lets you dismiss whole swaths of people because of the label you assign them. Lying, well, that has obvious advantages. These two are the heavier weapons, rhetorically speaking.
The cheap shots are nice zingers because they're short, sharp, and true. They problem is that they're skirmish weapons. They round out the arsenel, but they're best used sparingly. It's easy to come across as catty and mean. (Like mentioning Mary Cheney, for instance)
If the labels are wearing off, and the lies are being exposed, expect more cheap shots from our friends on the left.
Hey, if Rush wants to rail against sensible drug policies, he should be able to take the heat.
Cheap shot or no.