The U.S. Constitution is one of the oldest and most influential documents in the world. It has stood the test of time, but its strength is also its fundamental flaw: Today it’s almost impossible to change. The older the constitution, “the more people hold [it] with a kind of veneration, especially if [it’s] infrequently amended,” says Jill Lepore, Harvard professor, New Yorker contributor, and author of We the People: A History of the U.S. Constitution (Liveright, September 16).