Those political stereotypes are so....stereotyped. I have only one bumpersticker on my HCHII:
http://goats.com/store/item/sticker_rfv-1.html
(This presupposes that the reader is familiar with Harry Potter...)
additional hint: My wife and I use old calendar magnet sheets, stick the stickers to them, trim the magnets to fit, and slap 'em on our cars. Voila! No paint damage.