Beware of slippery-slope arguments. Once you accept one slippery-slope argument, you have to accept them all.
The people you're worried about are all happily typing away, posting juvenile comments on the story I submitted to politics.reddit.com yesterday. They have no motivation to come here. I think news.yc is safe regardless of what the editors decide about political stories.
P.S. My second sentence is a recursive joke. I didn't mean it.
It seems that in user-submitted and -voted content, moderation (in both senses of the word) is a problem.