I just ignore them; if they get obnoxious enough, I'll hide them from my newsfeed or unfriend them altogether (I've done both). I like FB for the lighthearted social interaction, not running political commentary.
"Maybe Lucy's right. Of all the Charlie Browns in the world, you're the Charlie Browniest."--Linus, A Charlie Brown Christmas
My fotki: http://public.fotki.com/nynaeve77/
Password: orphanannie