Photograph by Daniel Acker / Getty

Senator Elizabeth Warren has made a wealth tax one of the centerpieces of her Presidential campaign. The plan was developed with the help of the economists Emmanuel Saez and Gabriel Zucman, part of a new generation of economists whose work focusses on the failures of free markets and advocates for what many see as radical social change. John Cassidy joins Dorothy Wickenden to discuss how this cohort is affecting policy among the Democratic candidates, and whether the economy might help Donald Trump’s 2020 reëlection bid.