It's clear the United States isn't united right now. A Pew Research poll done before the 2020 election showed about 9 in 10 voters worried a victory by the other party would lead to lasting harm for the country. Our partisan divides aren't just endangering relationships and slowing progress in Washington, they're threatening our national security. "The greatest gift the United States can give to our national foes is hating each other. Why? Because it’s the ultimate distraction," says Arthur Brooks, professor at Harvard’s Kennedy School and Business School. He speaks with Amy Walter, editor and publisher of The Cook Political Report, and Susan Glasser, staff writer for The New Yorker, about this month's election results, the psychology behind our partisanship, what history shows us about division, and why there’s hope on the horizon.