Transformational Vs Transactional Leadership
Burns' theory (Burns, J. M. (1978). Leadership. New York: Harper & Row) ties this to morality by appealing to the values of the followers. I think you can see this in people like Martin Luther King or Winston Churchill. I think it is naïve to think that the hooks into people's beliefs and motivations are necessarily 'good'.
Bass's theory (Bass, B. M. (1985). Leadership and performance beyond expectation.