On a bitter cold day in 2007-nearly 150 years after Abraham Lincoln's inauguration-United States Senator Barack Obama of Illinois gathered his supporters at the old state capitol in Springfield, Illinois. Very new to the national political arena, he made an audacious announcement: "If you feel destiny calling, and see as I see, a future of endless possibility stretching before us; if you sense, as I sense, that the time is now to shake off our slumber,...