It was Abraham Lincoln who “struck off the chains of black Americans,” I have written, “but it was Lyndon Johnson who led them into voting booths, closed democracy’s sacred curtain behind them, placed their hands upon the lever that gave them a hold on their own destiny, made them, at last and forever, a true part of American political life.” How true a part? Forty-three years later, a mere blink of history’s eye, a black American, Barack Obama, was sitting behind the desk in the Oval Office.