Here's the thing, though: the staff doesn't read every post. Unless something is reported, there's a good chance we'll miss it. There's no bias if the staff isn't given a chance to edit the post.
EDIT: Here's the post I'm seeing: "We allowed stupid, greedy dishonest people to run the country for the last 8 years." Was there another one?
That's a far cry from calling all conservatives stupid and greedy. Now, whether the Bush administration fell into that category is a matter of debate, and I'm not sure how the staff would have responded if the comment was reported. I haven't examined the thread, for instance, to see how the post was supported, what the context was, etc. It's not necessarily against the rules to call a politician stupid, or greedy, or dishonest; rather, it's about the manner and context in which such arguments are made.
If the post had been reported, the issue would have been examined. It wasn't reported, and it was overlooked. To suggest that it belies some anti-conservative bias is silly.
Speaking as a conservative, I can say that many of the people who ran the country over the past 8 years were indeed greedy and dishonest. I tend not to think that most people at the highest levels are stupid, but I guess it's a matter of debate.