How on earth did the presumably educated and allegedly thoughtful American people – well into the 21st century – end up with a president as crude, crass, corrupt and downright cruel as Donald Trump? Not to mention stunningly incompetent?

God, I miss Barack Obama! Not to mention Bill Clinton and the two Bushes. Plus Jimmy Carter, Gerald Ford, Ronald Reagan, Lyndon Johnson, JFK. And Dwight Eisenhower. I liked Ike! As I recall, he was revered as a great general who won the war in Europe, and they say he was a genial golfer. Plus he gave us the interstate highway system.

And FDR – he was like a god!

Even Richard Nixon is looking pretty good these days, despite being a little – okay, a lot – corrupt. Before Watergate brought him down, he ended the draft, started the Environmental Protection Agency, signed Title IX – providing unimaginable opportunities for women – and visited China, opening it up for the West.

That feeling of rose-tinged nostalgia, I suspect, is shared by a great number of Americans. Which is why America is well on the path to impeaching our 45th president, although even if the House of Representatives does vote to impeach, it’s unlikely the spineless Senate will convict and remove him from office.

Not that the prospect of becoming just the third president to be impeached is daunting our perhaps excessively self-confident leader. He’s continuing in his contemptuous ways, including calling Republicans who criticize him “human scum.”

Donald Trump may have an unusually limited vocabulary, but he has little trouble coming up with derogatory terms for people he dislikes – like “failed,” “dishonest,” “fake,” “weak,” “lying,” “dope,” “crazy,” “nut job,” “phony,” “disgraced,” “sad” and – his favorite for women who make him uncomfortable – “nasty.”

There are a lot of nasty women out there in TrumpWorld.

Last week our president – who, let us remember, managed to get out of military service when a useful podiatrist diagnosed him with bone spurs in his feet – decided to spend a portion of his time disparaging a man who did serve, honorably.

That would be Lt. Col. Alexander S. Vindman, who was brought to this country from his native Ukraine by his immigrant father with his twin brother when they were 3 years old. They were taught to revere and to serve their adopted country, inspiring the boys to make their careers in the military.

Col. Vindman, an expert on his native country, was assigned to the White House and was one of those detailed to listen to presidential phone calls, a standard practice in all administrations. And – in the course of a congressional investigation – the colonel testified to what he heard on one call. Truthfully, it was proved.

But the man in the White House was livid. As he so often is. And while he didn’t attack Vindman’s heritage and record, his nastier acolytes did, implying the decorated veteran’s real loyalties were to Ukraine.

One Trump fan – John Yoo, the Bush administration lawyer who gave the green light to such torture as waterboarding – even questioned the decorated soldier’s patriotism and muttered darkly of “double loyalties” and “espionage” before general outrage erupted and someone yanked his chain back.

Finally, by the end of the week our fearless leader, having solved America’s problems, decided to heck with the maxim that U.S. politicians should avoid meddling in the internal affairs of our allies. Instead, he’d share his superior wisdom with the rest of the world – at least the small corner occupied by what’s left of the once glorious British empire.

So Donald Trump dialed in to a talk show hosted by his great good pal British anti-European Union gadfly Nigel Farage and suggested Farage team up with Boris Johnson, although the two are currently feuding. And for good measure our fearless leader also savaged the Labour Party leader, Jeremy Corbyn.

Which – because the Brits by and large loathe our fearless leader – gave Corbyn, widely viewed as a thoroughly unpleasant human being, an immediate boost in the polls.

Trump did have one big win this week – the death of the odious terrorist Abu Bakr al-Baghdadi – but obscured it by immediately plunging back into his usual feuds and schemes.

And so went another week in Trump World.

(“Monitor” columnist Katy Burns lives in Bow.)