There has been a continuous problem, dating back to founding of the United States, according to Jill Lepore, a professor of American history at Harvard University.

Lepore, the author of “These Truths: A History of the United States,” says Americans have had tremendous faith in the notion that technological innovations could heal our divisions and fix political problems. But that faith has frequently been misplaced or misguided. And ethical conversations around how to keep newspapers, radio, TV and other technologies in check, often come too late.