A world where the President can exclude outlets based on their reporting would allow any president to create a press corps of government sycophants.

Whatever folks think about the three outlets Trump singled out here (and remember that I'm a CNN analyst), a world in which the President can categorically exclude any outlet from the White House solely because he dislikes their reporting is one in which any president can construct a press room full of sycophants and other sympathetic mouthpieces for the government's policies.