As President Trump nears his 100th day in office, a new Washington Post-ABC News poll found that a historically low 42 percent of Americans approve of his job performance thus far. (Jenny Starrs/The Washington Post)

If happiness equals reality minus expectations, then we now know why President Trump is so unhappy with the media: His expectations were way too high.

“I used to get great press,” the president told the Associated Press in an interview published Sunday night. “I get the worst press. I get such dishonest reporting with the media. That's another thing that really has — I've never had anything like it before. It happened during the primaries, and I said, you know, when I won, I said, 'Well the one thing good is now I'll get good press.' And it got worse. … So that was one thing that is a little bit of a surprise to me. I thought the press would become better, and it actually, in my opinion, got more nasty.”

In these remarks, Trump once again displays a fundamental misunderstanding of the role of the media, which is to act as a check on power. As Trump has become more powerful — winning the Republican presidential nomination, then the White House — media scrutiny has intensified. That is both logical and appropriate, yet Trump believes the reverse should have happened. He said he was surprised that the media did not reward his winning by easing up.

We have seen this attitude from the White House before.

“I sincerely don't see a lot of difference in coverage from when he was a candidate and when he became the Republican nominee, the president-elect, and indeed the president,” counselor to the president Kellyanne Conway told CNN's Jake Tapper in February. “Some outlets, some people cover him the same way, and it doesn't have a great deal of respect, I think, for the office of the president's current occupant.”

On “The Late Show” with Stephen Colbert the next day, Tapper addressed the idea that the press should dial back, now that Trump is in office:

COLBERT: Should coverage change of Donald Trump, once he's the president? Should it change its tone?

TAPPER: I think that our coverage follows his lead. And I think if he pivoted, as he claimed he would and —

COLBERT: Be presidential.

TAPPER: Was more presidential —

COLBERT: More presidential than anybody's ever been.

TAPPER: If he didn't send out nasty tweets about Nordstrom's or judges or go to the National Prayer Breakfast and talk about how bad Arnold Schwarzenegger's ratings are —

COLBERT: They're pretty bad.

TAPPER: They're pretty bad?

COLBERT: Pretty bad, yeah.

TAPPER: But if he didn't do that sort of thing, then I would be delighted, frankly, to cover the policies more. I mean, not that we're not covering them. We are covering the Cabinet nominees and the travel ban, but there's this whole other thing going on with this White House.

It can be hard, at times, to figure out whether Trump is speaking strategically or genuinely. How could anyone be truly surprised that the president or a major-party nominee for president would have to go through the media wringer? Framing tough coverage as disrespectful seems like a political strategy designed to reduce its merit in the eyes of voters.

But it is possible that Trump really did not expect the press to cover him the way it has. He told the AP that he “used to get great press” and added that he has “never had anything like it before” — “it” being the scrutiny he receives now.

Those are true statements. For three decades, Trump was covered through various soft-focused lenses: reality TV star, beauty pageant owner, football team owner, golf course developer, professional big talker. It's not that he was never the subject of an unflattering article, but journalists didn't vet him like a future president because few, if any, imagined he would ever mount a serious campaign — never mind a victorious one.

Trump should have expected things to change, as he got closer to the Oval Office. But his long history of tame coverage set him up for an uncomfortable adjustment that he still has not made.