Yeah, don't vote for the SOB. And tell him so. When he thinks you won't have anywhere to go this November, prove him right... Don't go the polls.
If you want to send a message, not going to the polls is the worst thing to do. The best way to clearly send a message is to vote for a third party candidate. It would send more of a message that Bush has lost his conservative base if right wing third parties get 7-10% of the vote than if those unhappy voters do not show up in the election results.