Check out this review of Kerry's visit on Comedy Central

Dana Stevens remarks on slate.com are friggin hilarious.

Kerry's charisma was less than zero: It was negative. He was a charm vacuum, forced to actually borrow mojo from audience members. He was a dessicated husk, a tin man who really didn't have a heart. His lack of vibrancy, his utter dearth of sex appeal made Al Gore look like Charo. . . .
Watching Kerry strike out was especially heartbreaking given that Stewart was pitching not just softballs but marshmallows. Puffy interview marshmallows with rainbow sprinkles on them, and Kerry was letting them sail by as if he planned to get to first base on a walk. That may be how he hopes to win the presidency as well, but before he gets there, he'll have to jump through hoops a lot tougher than this exchange. . .

While it does appear Kerry is trying to at least take a few swings now, it might just be too little too late.