I'm liberal, and while I didn't find Pork Chop's joke funny on a purely humorous level (and not because I'm liberal, it just didn't have anything to it. I'd find it just as unfunny if it were a conservative insult), I most definitely did not take offense to it, and I don't think it does much good to make a big deal over something that is obviously a joke.
Oddly enough, for good JW's my parents talk about politics fairly often (but only among family members). Like me, they'd like to see Bush voted out of office in the upcoming election. They are, however, very socially conservative, as you'd expect from active JW's, whereas I'm basically a social libertarian (they thought that Bush's support for the gay marriage amendment was good, whereas I think the amendment is a bad thing). They're pretty socialist on their economic outlook (universal healthcare, massive wealth redistribution,etc.), whereas I'm fairly sympathic to a lot more conservative ideas in that direction (some privitazation of social security, school voucher choice, etc.), but I'm certainly open to some limited government help of the needy, and certainly government regulations insofar as cracking down on corporate crookery, as opposed to turning a blind eye to it because you received huge campaign contributions from the said crooks.
My parents are pretty suspicious of the military as you might expect, but I'm all for having a strong military with good weapons, etc. (but I'm with my parents in being against the Iraq war, because I think Bush presented a total lack of evidence for showing an eminent threat). Since my parents were "born JW's" just like myself, perhaps I'd have to ask my grandparents if they were politically liberal .