Others attribute it to admirably lefty British MP Ken Livingstone, who wrote an autobiography by that title following his term as London mayor.
Whether or not voting does actually change anything, a candidate had better behave as though it does. And "change" is the watchword during this presidential primary, even among Republican candidates whose policies can only be distinguished from the current neocon occupant's by virtue of the fact that they're not being read haltingly aloud in a whiny Texas/Maine accent.
That occupant, by the way, was famously described by Livingstone as "the greatest threat to life on this planet." So whatever change we may or may not get come Jan. 20, 2009, we'd better make sure it's a little less life-threatening than the George W. Bush administration.
