Douglas Brinkley and I are on the same page, we’re singing off the same song sheet, we are of like minds.

There. I don’t intend to cast myself as a knowledgeable presidential historian in the mold of Brinkley, but he has said out loud what many of us across the land have believed all along.

It is that Donald John Trump Sr. is “unfit for command.” He is not fit to hold the office he occupies. The president of the United States is in hopelessly over his head, out of his depth.

The basis for Brinkley’s harsh analysis lies in the “chaos” that pervades the White House. Brinkley points specifically to Anthony “Mooch” Scaramucci, the newly named White House communications director. Mooch has managed to accentuate the chaos by virtue of that hideous, profane interview he gave to The New Yorker in which he described former White House chief of staff Reince Priebus — and I hate using this terminology — as a “f*****g schizophrenic, a paranoiac.”

I must point out that Priebus was still the chief of staff when Mooch made that ghastly assessment. The president booted Priebus out of his job a few days later.

What kind of head of state and head of government allows an underling to use that kind of language in public to describe a fellow federal staff member? What kind of man tolerates that kind of behavior?

Oh, wait! It’s the kind of man who said years ago that he has grabbed women by their genitals; he has said Sen. John McCain was a “war hero only because he was captured” by the enemy during the Vietnam War; he is the individual who mocked a disabled journalist; he is the candidate who thinks nothing of lying and of defaming political opponents; he is a president who calls the media “the enemy of the American people.”

Many of us have believed all along that Trump is “unfit for command.”

Welcome aboard, Professor Brinkley.