Overview: The U.S. has long been a leader of democratic nations; a pillar of strength to its allies when facing communist countries or those with authoritarian leaders, although there are arguments concerning some of its foreign operations. But the events on January 6 may have lowered America's position. Some even say it was the darkest day in U.S. history. How will that day be remembered? What did it all mean? And how can the U.S. redeem its democratic standing? We asked Harvard historian Jill Lepore.