So what’ll it be, Bernie’s revolution or Hillary’s take-what’s-there politics? Really, you need both. It takes major energy to push the system to revolutionary change. But the revolution must thread the needle of the political system it scorns. The last president to combine the revolutionary’s sense of urgency with the political skills to get things done was Lyndon Johnson. He bludgeoned a sometimes reluctant Congress into transforming the country: voting rights, Medicare, the War on Poverty, the Clean Air Act -- all on his watch. He also made one huge error in judgment: Vietnam. The lessons of history are never simple.