Once upon a distant time — actually, it was only last week — a demagogue stood on a Phoenix stage and titillated his acoloytes by declaring, "If we have to close down our government, we're building that wall!" And with predictable Pavlovian passion, the naifs duly chanted, "Build that wall! Build that wall!"

It ain't happening. Unforeseen reality has blown that fantasy clear off the agenda.

All presidents are plagued by circumstances beyond their control, their best laid plans torn asunder. And this particularly weak president, with his 34 percent support and his zero congressional achievements, is now uniquely ill-suited to deliver pipe dreams to his Base.

Trump's ongoing blather about walling off the 2,200-mile Mexican border — with "a big beautiful wall" that "will go up so fast, your head will spin" because "nobody builds walls better than me" — has been snuffed by Tropical Storm Harvey. At a time when one of the nation's most pivotal red states is pleading for untold billions of federal dollars, there's no way whatsoever that Trump can foment, much less threaten, a federal shutdown in a quest for billions of wall dollars.

And if Trump somehow thinks it's still possible, the Republicans on Capitol Hill stand ready to disabuse him. Tom Cole, a senior GOP congressman from Oklahoma, says, "Congress wants to look functional ... You certainly can't have the government shut down in the middle of a national crisis." William Hoagland, a former budget adviser to Senate Republicans, says, "The truth of the matter is, they don't need money to build a wall in Texas, but to rebuild the shoreline in Texas."

Even the House's right-wing Freedom Caucus has decided that Texas' dire straits have taken wall funding off the table. Mark Meadows, who heads the group, tells ABC News: "In talking to a number of my members, if there was a vote for a continuing [budget] resolution next week that did not include border wall funding, the majority of those members would be supportive of that."

Politically, that's a wise decision; according to the latest Fox News poll, conducted prior to Harvey's devastation, only 39 percent of Americans support Trump's wall. And he's in no position to change people's minds, because the same poll says that only 33 percent believe he is "drawing the country together." By contrast, 56 percent say he's "tearing the country apart." (Did I mention that this was a Fox News poll?) Meanwhile, another national poll asked people if they'd support a shutdown in order to get the wall funded — and that idea was rejected in a landslide, 61 to 28 percent.

As recently as Tuesday, Trump still entertained the fantasy that he could have it all — untold billions for Texas, plus billions for the wall (MIT recently concluded that a wall would cost a minimum of $38 billion). Trump told the press that his push for wall money "has nothing to do" with the compelling need for Harvey recovery money. The wall issue, he insisted, "is separate."

Um, no it isn't. As a British politician named Nigel Lawson once said, "To govern is to choose. To appear to be unable to choose is to appear to be unable to govern." It's impossible to have it all.

Priorities are rapidly shifting. Conservative House Republicans (who, unlike Trump, at least have some governing experience) were planning, in a vote next week, to cut nearly $1 billion from the budget of the Federal Emergency Management Agency. That was befor Harvey. Post-Harvey, they now plan to boost FEMA's budget, not cut it. In the words of Jennifer Hing, a spokeswoman for the House Appropriations panel, "Given the current situation, the committee is reassessing the [FEMA] issue."

The perverse irony of Harvey — and nobody would have wished its deaths and devastation — is that the crisis could bring Republicans and Democrats together in common purpose: Help the victims (whatever it costs, because that's the overriding priority), keep the government open, hike the debt ceiling ahead of the looming deadline, and put the border wall in limbo (as Democrats have demanded all along).

As for Trump, he'll just keep doing what he does best — talk a good game about building the wall some day soon. It may never become a reality, but no matter, his rally-goers will keep gobbling his rhetorical popcorn. As he once said (or as his ghostwriter once said), "I play to people’s fantasies." True that. Playing is a whole lot easier than governing.

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