I do not normally find this guy particularly funny, but he hits the mark on this one.
White House West
(here is an alternate host of the same movie)
JibJab has a movie that pokes fun at both sides.
and lets not forget the quality efforts by MOVEON.org!
DT shared this with me....Billionaires for Bush
and on a non-US note....
here is a piece about a Tibetian Monk framed by the Chinese Government
the folks that put this together have a number of great FLASH animation pieces
go to FREERANGEGRAPHICS.com and check out their work