One of the great things about the DailyKos is that it tolerates reasoned dissent. In fact tolerance is one of the great things about the left side of the Blogsphere in general. One of the continuing themes at Kevin Drum's site is that trolls often attempt to hijack discussion. I think trolling is pretty common on other left/progressive sites. Frankly, I don't mind the trolls. If you can't handle dissent, your ideas are probably worthless.
This is not the case at
the Free Republic There reasoned dissenters find their posts pulled off the blog. I have heard that having a reality based post removed is a big problem on the right side of the blogsphere.