Now that Amy Coney Barrett has joined the Supreme Court, many are urging former Vice President Joe Biden to consider adding new seats to the Court if he's elected. But it's not the first time there's been talk of "packing the court." Princeton University professor Julian Zelizer looks at why Franklin D. Roosevelt wanted to add up to 6 seats to the Supreme Court in 1937, why it hurt him politically, and what packing the court in 2021 would accomplish.