Talking with Bob at lunch on Saturday, I realized that our differences on matters political can be boiled down to a single question: "If one is morally certain that a collective action problem exists but can be solved if someone is granted the power to enforce a solution, is it moral to enforce that solution?"
For instance, if there were an asteroid heading towards a destructive collision with the earth, would it be moral to tax people to blow it up?
I say the answer is clearly "yes": someone resisting paying such a tax is acting immorally. And coercing someone to prevent them from acting immorally is moral. Put another way: no one has a right to act immorally. (Nevertheless, it may not always be right to prevent them: I am not in favor of coercing people to be polite, for various reasons, but if it could be done in a way that would actually make them genuinely polite, it would not be immoral.)