"17 years since September 11th!"

President Donald Trump managed on Tuesday -- the 17th anniversary of Sept. 11, 2001 -- to simultaneously flout the most basic standards of decency and to make such norms seems quaintly irrelevant. 

The feat was no less spectacular for Trump having performed it so many times before: Weren't people still, like, curtsying in 2016?

Trump eased Americans into the day with some routine Twitter attacks against his Justice Department, before enthusiastically noting the passage of time.

Then, en route to Shanksville, Pennsylvania, to address a memorial service for Flight 93 -- on which 40 people died while thwarting a plot to crash into the US Capitol -- Trump was photographed fist-pumping as he greeted a group of supporters. 

Some of the president's critics were predictably triggered. 

Others needed no news peg to be outraged by Trump's shenanigans. The media -- social and otherwise -- exploded with ​reminders of his past self-aggrandizements and lies at the expense of the national tragedy:

Trump bragged on the morning of the Sept. 11 attacks that he now owned the tallest building in downtown Manhattan; he claimed to have seen Arabs in New Jersey cheering the downing of the Twin Towers; etc. 

MSNBC host Joe Scarborough went as far as to compare Trump to the terrorists who committed the Sept. 11 attacks. He penned an ​op-ed published Tuesday in The Washington Post in which he argued, “Trump is damaging the dream of America more than any terrorist attack ever could."

“For those of us still believing that Islamic extremists hate America because of the freedoms we guarantee to all people, the gravest threat Trump poses to our national security is the damage done daily to America’s images," he opined. 

The circle of recrimination was inevitably completed when Trump's supporters attacked his critics as ​idiots​morally deficient, or, screw it, traitors. 

Meanwhile -- lest the nation be left alone with its thoughts -- Trump sparked a new brouhaha. With a hurricane bearing down on the Carolinas, he lashed out of critics of his administration's response last year to Hurricane Maria in Puerto Rico, calling it "an incredible, unsung success."

Some 3,000 people are estimated to have died on the island in the aftermath of the storm.