I run into the issue of being repeatedly asked to judge the same comment all the time.
My record is eight times in a row. I assume it's a bug. It might be related to how much comments traffic is on this website at a given time. 
I'm liberal and I've also been blocked.
It's not a liberal/conservative thing.
It's a buggy program with comment-grading algorithms that end up being arbitrary and capricious.
I've judged a comment as civil, only to get a "black box" warning that I failed to meet standards and am blocked. If the algorithm is pre-judging comments, why bother with us? Unless it's to train us human beings to the computer program's standards.
Not quite "I'm sorry, Dave, I'm afraid I can't do that", but just another notch on the road there.