Sen. John McCain has emerged as President Donald Trump's top Republican nemesis on Capitol Hill.
Since Trump's inauguration, McCain has broken with the president on his immigration order, warned him against any rapprochement with Moscow and lectured him on the illegality of torture. He supplied only a tepid endorsement of Rex Tillerson, Trump's secretary of state nominee.
As Trump presses ahead with an ambitious and contentious agenda at home and abroad, McCain is pushing back, using his seniority in Congress and his characteristic bluntness.
McCain on Monday told reporters that Trump's immigration order bans Iraqi pilots from coming to the U.S. for training so they can join American troops in the fight against the Islamic State.
He says, "That's wrong."
McCain, 80, cruised to a sixth Senate term in November.