I say this only half-jokingly: How can they tell? Isn’t he always like that?

It’d be like writing of me, “Blogger glib, sullen, mildly intoxicated because of XYZ.” There’s no “because of.” That’s the default mode.

This might explain his no-shows at Aisne-Marne and Arlington over the past few days, though.

With the certainty that the incoming Democratic House majority will go after his tax returns and investigate his actions, and the likelihood of additional indictments by special counsel Robert S. Mueller III, Trump has retreated into a cocoon of bitterness and resentment, according to multiple administration sources…

[A]ccording to a source outside the White House who has spoken recently with the president, last week’s Wall Street Journal report confirming Trump’s central role during the 2016 campaign in quietly arranging payoffs for two women alleging affairs with him seemed to put him in an even worse mood…

“Not only did he barely show up [in Paris], he didn’t say anything that would help Americans understand the scale of the loss, or the importance of avoiding another great war,” [former Bush ambassador Nicholas] Burns said. “He seemed physically and emotionally apart. It’s such a striking difference between the enthusiasm he showed during the campaign and then going to Paris and sulking in his hotel room.”

He added, “The country deserves more energy from the president.”

Imagine how good it must feel to a Bush loyalist, after Trump destroyed Jeb two years ago, to throw “low energy” back in his face.

In all seriousness, though, read the Times story for the list of appearances Trump has missed or will miss this week. Skipping the visits to the cemeteries was curious; skipping all of the diplomatic stuff too has me a bit alarmed. The king of Jordan was in Washington today and didn’t get a meeting with POTUS. Mattis is headed to the Mexican border tomorrow to see how the deployment is going but Trump won’t accompany him. The ASEAN and APEC summits in the Far East are later this week but Pence, not Trump, will attend. Which is a big deal, according to one former White House aide who spoke to the LAT. Asian allies judge the president’s commitment to the region in part by his willingness to make the long trip and put in face time. Trump’s decision to skip it may affect diplomatic calculations in countries like Japan and South Korea.

Is the president under the weather, maybe? Or is he really so sulky about the midterms that he’s momentarily lost interest in the job? They did go pretty badly in hindsight, as I noted this evening, and Trump has more to fear than the average president does from a house of Congress flipping to the other party. Democrats are going to air his dirty laundry, and not just the administrative stuff. The personal stuff too. And the Mueller investigation will likely resolve soon, one way or another. Maybe he’s been given an inkling of how things are shaping up and is tending to that behind the scenes. If you believe the Spectator’s sources, Michael Cohen has now spoken to Mueller’s office and other prosecutors for no fewer than 80 hours. The president will certainly know the fallout from that before we all do.

Or maybe he’s worried about the 2020 map:

Here are three factors that should worry Trump and the GOP:

The midterm results were actually a terrible leading indicator for him. Turns out that without Hillary atop the ticket, Midwest states like Wisconsin are tough for Trump, and Southern states with rising Hispanic populations are slowly growing more Democratic. Long term, the GOP should be freaking out about this.

Trump and the GOP face two years of public investigations, coming from three different and dangerous directions: Robert Mueller, the state of New York and Congress. Two years of probing hell await.

The prolonged recovery is on borrowed time, and a recession could well hit at the worst possible time for Trump — in the thick of the presidential race. Live by the markets, die by the markets.

It’s hard to believe the Trumpian ego would ever allow pessimism about a popularity contest. Let me float a more prosaic explanation for his malaise: Maybe he’s just crashing after the weeks-long high of campaigning. Every politician enjoys seeing a friendly crowd but Trump seems to relish it in a way few others do. His off-the-cuff riffs at the mic sometimes sound like a chatty friend shooting the breeze with a buddy he hasn’t talked to in awhile. He spent two months basking in the adulation and now he’s back in his West Wing jail cell, having to police arguments among his staffers and figure out who the hell he’s going to staff the executive branch with after he fires half his deputies. It may be that he’s just bummed about all that, as any of us would be, and, uh … willing to jeopardize American alliances in the Far East while he works through it. Coulda happened to anyone.