The problem is, the average leftists are among the most self righteous and vindictive people on Earth. Anyway, what stops people who think they are absolutely right, from being jackasses, isn't jettisoning all common notions of right and wrong, ignoring the laws of man, God and nature......what's stops the self righteous from being jerks, is the virtue of humility. The left and right aren't lacking tons of people who think they're right about everything - what is lacking the ability to have charity for others who think differently and the humility to realize we don't know it all, even when we're sure we're absolutely right.