A good reason to start another list is that the parent list allows a topic which you do not want to discuss. The owner of that list is undoubtably a censor because he does not allow your opinion to become the guiding principle of the list. Whenever possible, be extremely civil to the owner of the list you are copying. Insist that nothing personal is meant by your starting a new list. Meanwhile keep telling your allies what a jerk the owner is and how much better you are.
Repetition is a good thing.
Repeat the above steps often.