Yes, I think Cartman is basically a representation of the archetypal psychopath.
There are a lot of bits in various South Park episodes which seem to hint at esoteric stuff, but I'm not really sure if it's done on purpose or if it's just a natural byproduct of the "make fun of everything" style..
E.g. check the episode about 9/11... in it, the boys meet a 9/11 truth movement group, who tells them the government was responsible for 9/11. while they are at this group's HQ, a SWAT team bursts in and arrests them all, taking them to the White House... there, GWB explains in detail how the government really was behind the attacks, and then shoots the 9/11 truth guy... the boys escape, but later see the 9/11 truth guy alive and well, and force the story out of him - it turns out that he's an actor, and *the government itself is behind the 9/11 conspiracy theories blaming the government*. So it's basically a description of COINTELPRO.
At the end of the show the reason given for the government pretending they did the attacks is "so that the public will think we are actually powerful and in control", and when one of the boys asks who was really behind it everyone says "a bunch of p#$%ed off muslims, duh" and laughs. These little bits at the end seem to me to be "masks" - like they are there to protect the show and make it seem as if it's all just a big joke - "oh it's harmless really". Of course I don't *know* this, I could just be seeing what I want to see :)
There's another SP episode in which a plague is ravaging America, coinciding with it becoming legal to say "sh$#" on TV. The boys figure out that curse words are just that - words which are cursed - and people saying them en masse brings about the curse, this plague.. It ends with them fighting a *dragon*, who was summoned by the mass saying of the S word.
Don't quite know what to make of lots of it, but there are a lot of little bits in SP that make me sit up and take notice. Maybe the SP writers sit around reading conspiracy forums on the net for story ideas or something :)
[edit]
oops, just noticed Deckard mentioned the 9/11 episode, and a thread about it, in the first post... doh!
I figured it hadn't been mentioned on here before because I couldn't find it with the search function.
*goes off to read the thread about the 9/11 ep*