Congressional Democrats on Friday called for an investigation into whether White House National Security Adviser Michael Flynn discussed U.S. sanctions in phone calls with Russia’s ambassador while President Barack Obama was still in office, conversations that may have broken U.S. law aimed at barring private citizens from conducting diplomacy. The White House said President Donald Trump had “full confidence” in Flynn, a show of support coming as the administration scrambled to manage the fallout from reports that Flynn addressed U.S. sanctions against Russia in a phone call late last year.