Since our nation's founding, the federal government has borrowed money from other governments, private investors, and businesses in order to operate. Over the last century, the debt ceiling, a Congressional cap on how much debt we can have, keeps getting higher and higher. We talk about how the national debt works, how it's been used as political leverage, and how that impacts the health of our economy. Louise Sheiner, senior economics fellow at the Brookings Institution, and Michael Dorf, Constitutional law professor at Cornell Law, help us make sense of trillions of dollars in debt.