One of the big stories of the 2016 Presidential campaign was the role Facebook played in spreading false and misleading information, from Russia and from inside the United States, about candidates. The company has made some changes, but it is still under attack from the press, activists, users, and Congress for its failure to curb the proliferation of “fake news” on its platform. Mark Zuckerberg, Facebook’s co-founder and chief executive, announced this fall that Facebook will not fact-check political advertisements or other statements made by politicians on the platform. Evan Osnos joins Dorothy Wickenden to discuss social media’s power to shape politics and the likely effects on the 2020 Presidential campaign.