The Fix's Callum Borchers explains the years-long feud between President Trump and the hosts of MSNBC's "Morning Joe." (Peter Stevenson/The Washington Post)

People suffering from Alzheimer’s often experience something called “sundowning,” when in the early evening they become particularly disoriented and erratic in their behavior. The president of the United States experiences something we might call “mornraging,” when at the beginning of the day he tunes in to morning television shows, hears something that makes him mad and fires off tweets that highlight the darkest recesses of his id.

At the precise moment when President Trump is trying to persuade Republican senators not to abandon one of the party’s most critical policy initiatives, it’s almost as though he’s trying to give members of his party reasons to get as far from him as possible. That could have continuing consequences for the party’s ability to achieve tricky and complex policy and political goals.

Here’s what Trump sent this morning:

If Donald Trump were your friend, your uncle or your co-worker, you’d feel compelled to say to him, “Dude, c’mon. Don’t be such a jerk.” But he’s not any of those things. He’s the president of the United States, the most powerful person in the world.

And some Republican members of Congress are indeed telling him to stop being such a jerk. “This has to stop – we all have a job – 3 branches of gov’t and media. We don’t have to get along, but we must show respect and civility,” tweeted Sen. Susan Collins (R-Maine). “Please just stop. This isn’t normal and it’s beneath the dignity of your office.,” added Sen. Ben Sasse (R-Neb.).

“Mr. President, your tweet was beneath the office and represents what is wrong with American politics, not the greatness of America,” said Sen. Lindsey O. Graham (R-S.C.). “The President’s tweets today don’t help our political or national discourse and it does not provide a positive role model for our national dialogue,” said Sen. James Lankford (R-Okla.).

“This is not okay,” said Rep. Lynn Jenkins (R-Kan.). “As a female in politics, I am often criticized for my looks. We should be working to empower women.”

But he won’t stop. This is who he is. We all know that. Trump is not going to become “presidential,” he’s not going to rein in his worst instincts, and he’s not going to stop mornraging. He’s a petty, vindictive, insecure little man with no impulse control. It’s who he is and who he will always be.

After President Trump tweeted insults at MSNBC host Mika Brzezinski on June 29, White House principal deputy press secretary Sarah Huckabee Sanders defended Trump and said Americans "knew what they were getting" when they elected him. (Reuters)

Republicans knew exactly who he was when they all lined up behind him in 2016, even if many harbored the naive hope that he would be changed by the office. But they also assumed that with total control of the government, they would pass a boatload of bills, he’d sign them, and his personal weaknesses wouldn’t much matter. It turns out, however, that it isn’t so simple. As we’re seeing in the health-care debacle currently underway, when you’re trying to accomplish something complex and politically perilous, you need the president. You need him to be a persuasive public advocate for your policy, and you need him to help resolve internal differences and forge consensus.

But Trump fails on both both counts. He can’t be a persuasive advocate because he doesn’t understand the policies he advocates for, and he has focused so relentlessly on telling his base what they want to hear that people outside that base just don’t believe him. When he gives an interview or makes a speech about what Republicans are trying to do, he’s likely to say something that contradicts or undermines their case. And internally, he’s rapidly losing whatever respect he had from Republicans.

Consider this description from a recent article by some of The Post’s political reporters about how Trump is viewed by members of his own party in Congress:

In private conversations on Capitol Hill, Trump is often not taken seriously. Some Republican lawmakers consider some of his promises — such as making Mexico pay for a new border wall — fantastical. They are exhausted and at times exasperated by his hopscotching from one subject to the next, chronicled in his pithy and provocative tweets. They are quick to point out how little command he demonstrates of policy. And they have come to regard some of his threats as empty, concluding that crossing the president poses little danger.

Republicans are facing some tricky challenges in the months ahead — passing a budget, increasing the debt ceiling, tax reform — and success can require subtle negotiations. At times, it may be necessary for the president to convince individual members to put aside their own ideas and interests in favor of something that is good for the party but might not be good for them. Who thinks Trump is capable of that?

Now let’s be clear about something: Republicans are not a profile in courage on the question of Donald Trump’s boorishness. They supported him in 2016 — when he was accused by multiple women of harassment, when he made racist attacks on a judge, when he picked a fight with a Gold Star family, when he was caught on tape bragging about his ability to commit sexual assault with impunity — and they still support him as long as he’s doing what they want. There are precious few of them who stood up and said that they could not in good conscience stand behind such a despicable human being, and history will judge them harshly for their complicity in this disaster of a presidency.

But what I’m talking about here are the moments when they aren’t all in agreement, and Trump would have to exercise leadership to pull them together. If you’re a member of Congress, making the decision to overcome your doubts and do what the president asks isn’t easy. A lot of factors play into it — your fear that he might punish you, the personal relationship you’ve built with him, your constituents’ feelings about him, your worries about reelection, your belief in your own independence and so on. Trump has been president for barely five months, and we’re already seeing that members of Congress don’t really fear him, they’re continually amazed by his ignorance about policy, and they think his White House is a bunch of amateurs.

Trump could change that state of affairs, but it would take time, work and an inclination he apparently lacks. Instead, he’d rather just say that everything is going great. So he keeps making it worse. If you’re in the midst of sensitive negotiations over health care and you desperately need to hold the votes of (among others) Sens. Collins, Lisa Murkowski (R-Alaska), and Shelley Moore Capito (R-W.Va.), maybe launching puerile sexist tweets at cable news personalities is not going to help.

There are always going to be times when a member of Congress says, “Mr. President, I respect and admire you, but I have to say no this time.” That happens to every president. But if you convince them that you’re not worthy of their respect and admiration, saying “No” becomes a lot easier.