I'm not a lawyer, but I believe the point isn't necessarily that you'd use civil disobedience as an affirmative defense (like a self-defense claim would be). Instead, you'd make that argument to a jury that may or may not factor that into their decision (i.e. jury nullification). You're right that it's not a claim you'd make to a court expecting leniency. But you might be able to gain sympathy from a jury of your peers if they thought you were morally right.
I don't think there is anything that would stop a defense from making that argument. If that's all you had to argue, then that's the proverbial "pound the table", if you will.
I don't think there is anything that would stop a defense from making that argument. If that's all you had to argue, then that's the proverbial "pound the table", if you will.