I'm jumping in half-informed and half-cocked, but here goes.
It's darned hard to moderate any blog, especially a political one. People are going to get fired up, and they are going to push the limit to fire up the other side. Seriously, how many comments are actually meant to persuade? Darned few, though CBlog seems to have it a bit better than other blogs.
A junior high history teacher taught me a very important lesson that I've carried with me to this day. Laws and rules are like a coastline and the grey areas are the shallow rocks that can wreck your little ship. So if you don't want to run the risk of hitting the rocks, steer well clear and don't push your luck. It's the same with discretion. If you don't want someone to rule against you, stay in safer water and don't give them the opportunity.
Given what I've seen the mods here do a good job. It's one of the reasons I love Celtics Blog. On the other hand, Cordobes may be completely right (no pun intended). I don't know. However, in the end, it's the bloggers responsibility to make sure that a mod doesn't have to make a tough decision.