President Trump tosses paper towels into a crowd of Puerto Rico residents. (Evan Vucci/Associated Press)

More than 80 percent of Puerto Rico is still in the dark, more than a third of its residents still have no clean drinking water, much of the island's infrastructure still lies in ruins — and President Trump cruelly threatens to cut off federal aid. Doing so would be government by spite and should be considered an impeachable offense.

Puerto Rico, as any fifth-grader knows, is part of the America that Trump promises to make great again. But the mayor of San Juan had the temerity to criticize the Trump administration's response to the calamity of Hurricane Maria as slow and inadequate. For Trump, everything is always all about Trump. He desperately craves adulation.

The president complained Sunday on Twitter, "Nobody could have done what I've done for #PuertoRico with so little appreciation. So much work!" Note the use of "I" instead of "we" or even "my administration." For the record, what Trump has done personally for the people of Puerto Rico is playfully toss rolls of paper towels into a crowd.

The administration has done much more, of course. But desperate people — still facing critical shortages of food and water three weeks after the storm — are demanding more action. This makes them “ingrates” in Trump’s eyes.

Sadly, those are the kinds of words we've come to expect from this president. But on Thursday he went beyond his usual self-pitying, self-justifying blather to make an outrageous threat: "We cannot keep FEMA, the Military & the First Responders, who have been amazing (under the most difficult circumstances) in P.R. forever!"

That culminated a series of blame-the-victim tweets about how Puerto Ricans face "a financial crisis . . . largely of their own making" and how "electric and all infrastructure was [a] disaster before hurricanes." The need to solve the island's debt problem and update its infrastructure is worthy of serious discussion, but not while people are having to collect unpurified water in buckets from mountain springs — and not as some kind of justification for cutting off relief aid.

This may be the most un-American thing Trump has ever said or done. I am serious that if he actually withdraws emergency assistance while Puerto Rico is still in such condition, Congress should begin impeachment proceedings.

Presidents do not get to pick and choose which Americans to help at times of disaster. We are one country, and we do what we must to help fellow citizens in need. We saw it during this long, terrible hurricane season, in Puerto Rico, the Virgin Islands, Texas, Florida — strangers helping strangers, regardless of race, income, political views. We are seeing it now as firefighters from around the country converge on Northern California to attack the deadly blazes that are still burning out of control.

It is wrong to describe Trump as any kind of nationalist if he fails to grasp the most fundamental of nationalistic precepts: We leave none of our own on the battlefield.

The responsibility of the federal government is to keep FEMA workers, military personnel and other first responders in Puerto Rico as long as necessary. It is important to do so because their presence will save lives. It is also important because doing anything else would violate the American compact. If Trump really were to turn his back on Puerto Rico, he would be guilty of a “high crime” and disqualified to continue in office.

I know that Trump delights in violating political norms and causing the commentariat to run around with its hair on fire. I know that he sometimes says provocative things on Twitter to distract from his administration’s failures, to rally his base, to provoke his enemies or even just to blow off steam. I know that it’s impossible to take any one tweet too seriously, because it may be directly contradicted by the next tweet.

But Trump actually went to Puerto Rico, and while he did not see the worst of the devastation, he saw more than enough. He knows that recovery is going to be a long, massive and largely thankless job. But that is the job he signed up for when he took the oath of office. Congress must not allow him to shirk his duty.

To divide the country with rhetoric, as Trump so often does, is one thing. But to actually abandon 3.4 million Americans in their hour of need not only would be an unprecedented and shameful act. It would also be grounds for removing an unfit man from the high office he dishonors.

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