I agree djk. It is so easy to use the Nazi's and Hitler as metaphor but in reality the terror of the Nazi regime is far beyond the actions of Bush or many other's that are compared to Nazis. I fear that these comparisions serve to diminish the terror that the Nazi wreaked on our world.
I believe what the Bush government has done in Iraq is wrong but it hardly puts him in the same league as Hitler.
I wish I could agree with you that this kind of attack only serves to turn off voters. Unfortunately studies have shown that the negative advertising during election campaigns in the U.S. has been quite effective.
While I strongly disagree with using Nazi symbolism I would suggest that you might want to have a look at the 30 second ads from a contest sponsored by move on.
http://www.bushin30seconds.org/
fa