Trump lawyer claims the "President cannot obstruct justice"

John Dowd, President DonaldTrump's outside lawyer, outlined a new and highly controversial defense/theory in the Russia probe: A president cannot be guilty of obstruction of justice.  The "President cannot obstruct justice because he is the chief law enforcement officer under [the Constitution's Article II] and has every right to express his view of any case," Dowd claims. Dowd says he drafted this weekend's Trump tweet that many thought strengthened the case for obstruction: The tweet suggested President Trump knew Michael Flynn had lied to the FBI when he was fired, raising new questions about the later firing of FBI Director James Comey. Dowd: "The tweet did not admit obstruction. That is an ignorant and arrogant assertion."