All of the great leaders have had one characteristic in common: it was the willingness to confront unequivocally the major anxiety of their people in their time. This, and not much else, is the essence of leadership. (John Kennneth Galbraith)

For change to succeed during a period of crisis there is a major need of vertical interaction, that is interaction between elites with enlightened self-interest and grass roots. An often referred to example of this is of course New Deal.