Media playback is unsupported on your device Media caption Trump's tweets: Four women, two takes

It is tempting to dismiss the row between Donald Trump, President of the United States, and Mika Brzezinski, host of a US TV show, as a vaguely self-referential media story that most Americans care little about.

Tempting, but wrong.

Yes, this story risks making the media the story - rarely a good thing - and risks making the media look even more out of touch with average US voters who have more pressing economic concerns.

That doesn't mean it isn't serious. It tells us things about the man and about his presidency, things that are worth knowing.

Full disclosure: Mika Brzezinski is a friend of mine and we work together regularly on her show. But this story is really not about her at all. It is what it tells us about the president that matters.

1. The way President Trump talks about Brzezinski in those tweets is sexist. What's more it is just the latest in a string of sexist comments that focus on women's looks, not their abilities. Rosie O'Donnell, Megyn Kelly, Carly Fiorina, Miss Universe, Brzezinski are just a few. Sexism like this from the top can breed sexism down the line, it can make it seem somehow acceptable. It isn't.

Image copyright EPA Image caption What do Mr Trump's tweets say about him?

2. Using personal information of this nature against someone is singularly vicious. As Melania Trump says, when Donald is attacked he hits back ten times harder. In this instance Mr Trump used the platform of the Oval Office and his Twitter feed to magnify the force of the blow.

The White House says this makes him tough and a fighter and that's why he was elected. I wonder about that. Do Americans who elected him to fight for their jobs actually want him to use that same quality in this way?

3. The tweets show he is easily provoked. America's allies and adversaries are taking note.

4. The incident suggests his anger can take precedence over political expedience. Right now Mr Trump needs Republican Senators to support his healthcare reform. Several of them immediately expressed extreme dismay at these tweets, saying they were beneath the dignity of the office. It may not impact their final vote, but it can't help.

Media playback is unsupported on your device Media caption A video obtained by the Washington Post shows Republican presidential candidate Donald Trump making lewd remarks about women

5. Criticism, however strongly worded or teasingly expressed, comes with the job of being president. In 1962 after the Bay of Pigs fiasco JFK talked about how he'd been pummelled by an "abrasive" US press corps - he also said that was a good thing because it made his presidency stronger.

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6. Members of Congress and members of the administration have now spent the past two days being forced to answer questions about facelifts and blood. The President may rightly think conflict with the media rallies his base but it distracts people around him from focusing on the job of health care and tax reform and infrastructure bills. That's not useful, for anyone.

7. The National Enquirer/Trump/Morning Joe story needs further investigation. Until we have all the facts it's hard to make an assessment.