As the nation is reeling from President Trump's executive order on immigration, one Boston College historian argues that the order has been designed to throw society into chaos — something called "a shock event."

"Unless you are the person setting it up, it is in no one's interest to play the shock event game," Heather Cox Richardson wrote on Facebook Sunday. "It is designed explicitly to divide people who might otherwise come together so they cannot stand against something its authors think they won't like."

Cox Richardson said the country has experienced shock events before, for example, in the run-up to the Civil War. Looking at that history, she says, people can also learn how to use a shock event to create unity.

Guest

Heather Cox Richardson, history professor at Boston College and author of "To Make Men Free: A History of the Republican Party." She tweets @HC_Richardson.