Because they are certain they are correct. Correct about God, correct about birthright, correct about politics, correct in judgment of others, correct in their self-superiority. As such, they're above any societal structure put in place to control the inferior people. With The Truth on their side, nothing is unjustified, including unlawful acts against society. For them, the law is just another belief that they can choose to believe in, or discard, ridicule or actively combat, when it fits their needs (which, again, are always justified).
Sounds familiar, doesn't it?