Redditors have done it. Jon Stewart/Stephen Colbert rally in DC 10/30/10.

It started with this post: http://www.reddit.com/r/politics/comments/d7ntl/ive_had_a_vision_and_i_cant_shake_it_colbert/

And they donated more than $240k to Donors Choose on Stephen Colbert's behalf to convince them: http://www.colbertrally.com/

Jon and Stephen's announcements:

http://www.rallytorestoresanity.com/

http://www.keepfearalive.com/

Amazing.