President Donald Trump is embarrassing himself and the nation with his public Twitter rants against anyone he believes has offended him.

Whether Trump is going after television talk show hosts, former President Barack Obama or whole nations, he is lowering the dignity of his office. What’s more, he is displaying, by his actions, that it is all right to insult, to belittle and to berate those with whom you disagree. And when Trump sent a tweet Thursday morning insulting MSNBC hosts Joe Scarborough and Mika Brzezinski, he showed once more his disdain for women. The story has grown from the initial tacky tweets — Trump also is being accused of attempting to blackmail the MSNBC hosts with bad publicity in the National Enquirer if they didn’t apologize for criticisms.

His latest: “I heard poorly rated @Morning_Joe speaks badly of me (don’t watch anymore). Then how come low I.Q. Crazy Mika, along with Psycho Joe, came …

… to Mar-a-Lago 3 nights in a row around New Year’s Eve, and insisted on joining me. She was bleeding badly from a face-lift. I said no!”

Remember, this is the man who bragged about grabbing women’s genitals and who attacked then-Fox host Megyn Kelly, saying she had “blood coming out of her wherever.” Just last week, he interrupted a phone call with the Irish prime minister to compliment a female reporter, calling her over and saying, “she has a nice smile on her face, so I bet she treats you well.”

His tweets about the two TV stars were so vulgar that even Republicans called out the president. GOP Sen. Ben Sasse of Nebraska summed it up best, tweeting, “Please just stop. This isn’t normal and it’s beneath the dignity of your office.”

Not only does it lower the standing of the president before the nation and the world, this impulsive and petty tweeting sets a bad example. Parents everywhere now must explain to their children that, no, they should not aspire to be like President Trump. Educators are reporting instances of bullying in schools, with children mimicking the words of the president as they badger their fellow students. In Kentucky, a third-grade boy chased a Latina girl around their classroom, shouting, “Build the wall,” a signature Trump phrase. That’s just one of a number of ugly incidents taking place in playgrounds and schools across the country. After all, if it’s OK for the president. …

Years of progress in achieving equal rights for women are being set back. That’s why a president who thinks nothing of insulting women is a big deal. There are practical implications for his misogyny, too. He is alienating supporters he needs to push his legislative agenda.

The president wants an “Obamacare” repeal and replacement bill to pass in the Senate — and he needs the votes of female GOP senators to reach that goal. From moderate Republican Sen. Susan Collins of Maine: “My first reaction was that this just has to stop, and I was disheartened because I had hoped the personal, ad hominem attacks had been left behind, that we were past that.” Alaska’s GOP Sen. Lisa Murkowski — who opposes the current version of the Senate health care bill — was no less blunt: “Stop it! The presidential platform should be used for more than bringing people down.”

Nicolle Wallace, former communications director in the George W. Bush White House and current MSNBC host, summed up her frustration with the president’s increasingly boorish behavior. She demanded an apology from Trump and said that the women in the White House have an obligation to condemn his actions.

“As someone who once proudly called myself a Republican, the party will be permanently associated with misogyny if leaders don’t stand up and demand a retraction,” she went on to say, ending with this powerful warning. “As a mother of a son, I ask any woman who is defending these comments how they plan to raise good men, if the most powerful man in the world gets away with this.”

The most powerful man, yes. But also the most petty.

As former first lady Michelle Obama famously said: “When they go low, we go high.”

For Donald Trump, this is the saying: “When they go low, we go lower.”

Try explaining that to the kids.