Interesting. Good for him to refuse to be their trained monkey, invited only to get the laughs (although i did think a lot of it was funny). I'm not sure I like the preachiness, but if the guy's got something to say he should say it, even if it would be more entertaining in a bit with Rob Corddry.
I wonder if they'll have Carlson on TDS for a continuation, like they did with O'Reilly after the stoners comments. O'Reilly was actually one of the better guests they've had on of late, despite the involuntary snarl I get whenever I see him on the teevee.