As we’ve said here before, Donald Trump has to learn to just shut up and let things go.

The failure to do that is the worst Achilles heel of a president who seems to have half a dozen Achilles heels.

Because he can’t think on his feet, because he doesn’t know how to say the right thing at the right time, because he thinks he’s got to win every petty argument with the anti-Trump media, the president has mired himself unnecessarily in yet another controversy of his own making.

This time it’s Charlottesville.

Who didn’t know in advance there was going to be big trouble in that Virginia college town last weekend?

You had the dregs of this country’s minuscule right-wing hate sector — about 500 white nationalists, the KKK, neo-Nazi groups and assorted allies and hangers-on — coming from hundreds of miles in every direction under the pretext of legally protesting the planned tear-down of a statue to General Robert E. Lee.

You had their violence-prone left-wing opponents — organized groups like Black Lives Matter and Antifa — pouring in from out-of-state to protest the presence of the white nationalists.

The right-wing hate groups marched around the town Nazi-style, chanting anti-Semitic and anti-black slurs, exercising their First Amendment rights and putting their moral and political ugliness on full display.

Who didn’t know the anti-Trump media was going to be there en mass to record everything?

Who didn’t know the liberal media would seek out a visiting professional racist like David Duke and get him to say something nice about President Trump on camera?

Well, apparently President Trump and his staff didn’t know.

They certainly weren’t prepared to respond to the predictable violence, which in this case included the tragic death of a young woman run down by a hater who deliberately drove his car into the crowd of people protesting the marchers.

Charlottesville should have been a no-brainer for the White House — and it should be finished business.

The president should have read a simple prepared statement last Sunday that was written by someone who knew what to say and how to say it.

He should have said, quickly and clearly, that the white nationalists, the KKK, the neo-Nazis and their fellow haters were despicable Americans with un-American beliefs — true deplorables, if you will.

He should have reemphasized that they and their ilk did not speak for him or his administration. Ditto for the David Dukes of the world.

Then the president should have issued the standard presidential condolences and moved on to tax reform or North Korea or whatever important issue he has on his unfinished plate.

Charlottesville was never Trump’s fight. He should have stayed out of it — above it — and acted presidential, which, I know, is asking a lot.

Instead he again took the media’s bait — and then did his usual clumsy job of engaging a pack of rabid reporters in full view of the world.

He tried to equate extremist white nationalists with left-wing protest groups like Black Lives Matters.

Yes, it’s true that BLM protesters have stirred up violence and said nasty things about cops. And it’s true the militant hard-left group antifa uses fascist street violence in the name of fighting fascism.

But they are not the equivalents of the racist right-wingers whose “ideas” include virulent anti-Semitism, the natural superiority of whites, white separatism and a call for America to get rid of all non-white immigrants.

It’s true, as Trump said, that both sides in Charlottesville engaged in acts of street violence.

But the president was wrong. There is no moral equivalence between the hard-left groups and hard-right groups, and because he tried to make the case there was he’s made a bunch of new enemies and lost some old friends.

He has yet to learn that when you’re the president you have to know when to shoot back, when to change the subject and when to just shut up in first place.

Copyright ©2017 Michael Reagan