President Barack Obama used a pseudonym in email communications with Hillary Clinton and others, according to FBI records made public Friday. The disclosure came as the FBI released its second batch of documents from its investigation into Clinton’s private email server during her tenure as secretary of state. The 189 pages the bureau released includes interviews with some of Clinton’s closest aides, such as Huma Abedin and Cheryl Mills; senior State Department officials; and even Marcel Lazar, better known as the Romanian hacker “Guccifer.” In an April 5, 2016 interview with the FBI, Abedin was shown an email exchange between...