Jon Stewart held a rally on the National Mall a couple months ago, as we well know. The theme was restoring sanity, a serious response to outrageous rhetoric by politicians and journalists presented in a tongue-in-cheek way.
Lately on The Daily Show Jon himself has been getting a little flustered over the way Congress continues to not vote to approve a bill to provide money for medical expenses of the first responders on 9/11. On last Thursday night's show he had four men who were down at Ground Zero that day, heroically trying to save those in the rubble, and who all now have serious medical issues. It's not even a subtle axe that Jon is grinding here.
I can see as how detractors might allege Stewart of being somewhat irrational in his dogged harping on the government (and the media who is not covering this story), thus making him something of a hypocrite. However, being passionate about something is not the opposite of sanity; the irrational response to what one perceive as a hideous injustice is to get riled up about it.
Of course, the danger of all of this is it makes it seem like Stewart could become the activist that the progressives want him to be but which he categorically refuted being in interview after interview (in promoting the rally). If this effort actually influences either the elected representatives to action or at least the media to pick up the story again, it will suggest that he's more than the comedian he has always claimed only to be.
But if it gets help for those who risked their lives nine years ago whose lives are now literally at risk, I imagine that's a burden he'd be willing to carry.