Rikki Klieman: "Of course a president can obstruct justice"
There is new talk over what President Trump knew when he fired National Security Adviser Michael Flynn. CBS News legal analyst Rikki Klieman joins "CBS This Morning" to discuss the debate over whether a sitting president can be charged with obstruction of justice, the possibility that Mr. Trump's tweets could be used as evidence in an impeachment trial, and the "major shift" in the president's defense strategy over allegations of Russian collusion.