CNN reporter says Trump broke 'first rule of Washington -- never compare things to Nazis'

Donald Trump was elected president despite violating nearly every political norm -- but his approval rating has sunk to 40 ahead of Friday's inauguration.

The president-elect is currently embroiled in several running social media disputes with lawmakers and intelligence officials, including CIA director John Brennan and Rep. John Lewis (D-GA).

"He doesn't get why it's out of bounds, he's just popping off because that's how he's always done it," said reporter Jonathan Martin, of the New York Times. "It worked in the campaign, so why stop now?"

CNN's John King wondered whether Trump understood political norms and ignored them, or if he simply didn't understand the boundaries that constrained political disagreements.

"He thinks, 'That's the problem in this town, and I'm going to do things differently,'" King said. "'If you're not nice to me, I'm going to get you. If you don't kiss the ring, you know, I will attack you.'"

CNN political reporter Sara Murray said the president-elect had violated one of the bright-line boundaries of political discourse when he compared U.S. intelligence agencies to the Nazis.

"The first rule of Washington is don't compare things to Nazis," Murray said. "The second thing is, don't compare anything to rape. Those are the two things that will get you in trouble. Never say it, never do it."