What Donald Trump's verbal takedown of Mark Sanford reveals about him

Trump asked whether the South Carolina Republican, who lost a primary last week largely due to his willingness to publicly criticize Trump, was in the room. Upon being told Sanford wasn't in attendance, Trump ran him down as a "nasty guy," according to sources in the room.

"There were a few moans," Rep. Mark Walker, R-North Carolina, chairman of the conservative Republican Study Committee, told CNN about the moment. "Mark's one of our colleagues, and agree with him or not, he's an honest man."

It's a minor moment, but a revealing one for Trump. Here's what it says about the President:

1) He's a bully

Trump likes to run people down. He did it throughout the 2016 Republican primary campaign. He's done it in the White House. He has power and he likes to wield it, often in crass ways. That Trump checked whether Sanford was there, found out he wasn't, and then proceeded to kick the defeated member while he was down is incredibly telling.

2) He can't read a room

If there's one thing that can unite a divided conference like the House Republicans, it's sympathy for one of their own losing. Every time a member of Congress loses in a primary, every other member thinks "Man, that could have been me." Trump seems blithely unaware of that reality. Or he doesn't care. No matter. It amounts to the same thing -- by attacking Sanford, a guy who already lost his job because of Trump, the President saps out even more goodwill from even the Republican members who support him.

3) He's not a gracious winner

Here's the thing about Sanford: He lost. And he lost expressly because he criticized Trump. His opponent ran a campaign that amounted to this: Mark Sanford sometimes criticizes President Trump. I won't do that. It's over. Sanford won't be back in Congress. He learned his lesson -- or something. And yet, Trump can't let his victory be. He has to attack Sanford -- in front of his soon-to-be former colleagues no less -- to prove his dominance. To remind people what happens when you cross Donald Trump. What Trump did on Tuesday night amounts to going into the locker room of a team you just beat and reliving how you scored the game-winning goal.

For regular Trump watchers, none of this is new territory. Trump has demonstrated his bullying tendencies before. He's shown that he doesn't tailor his message to an audience. He has lorded wins over the people he's beaten.

But what it does show is that Trump is not evolving as President. He is the same person he has been for his entire life. If anything, he's become an even bigger version of that person -- a proof point for Michelle Obama's now-famous quote that "the presidency doesn't change who you are, it reveals who you are."

There is no Trump other than the Trump we see every day in public appearances and on Twitter. He's the same person in a private meeting with Republican House members, out on the campaign trail at a rally or typing out a tweet on his phone. What you see is what you get. Period.