It's the voters, stupid.
So?
The election is the candidate's to lose. They..even Bush...can blame nobody but themselves, especially if they lose because they turned away from their core supporters.
When you leave the ones who brung ya' behind, you can't blame third parties for your loss.
Similarly, there was a time to make one's protest heard - it was local elections and state elections and elections to the House and even the Presidential primary. However the voter now has to ask - will the ideals they want to push forward be best served by contributing to a Kerry victory? Unlikely.
Having said that, I hope our left wing friends are more mad than we are in the pursuit of purity over practicality. ;)
Regards, Ivan
Half the people don't bother or care enough to vote...and yet everyone demonizes third party candidates because they attract a small percentage of actual voters.