In his poem, “Mending Wall,” Robert Frost says that whatever it is that does not love a wall “wants it down.”

But our president (who unlikely to have read much poetry) has walled himself into an intractable corner where he — with his back to the wall for which he lusts — is doing what any cornered animal does: hiss and bark and threaten, hoping we will be as frightened as he and the Republicans are of living as Americans have for more than two centuries: without Trump’s wall.

Frost has good advice for those who trust or pretend to believe in the necessity:

Before I built a wall I'd ask to know

What I was walling in or walling out,

And to whom I was like to give offence.

That’s darn good advice, and most of us haven’t spent enough time wondering about the answer. Nancy Pelosi says a wall is immoral, but provides little defense or detail for her ethics. Nevertheless, the image of children separated from their parents and sleeping on concrete floors has so alarmed the U.S. citizenry that Trump argued in his address to the nation Tuesday that his wall actually protects women and children — by discouraging them from emigrating.

Is our president really so dull that he doesn’t know the dangers from which they are escaping? Or does he care less than he pretends?

The evidence suggests his is more a political than a moral argument, an expedience rather than a crisis. (Depending on your factoring, interdictions, arrests, recidivism and other evidences of illegal immigration are at a 10- to 40-year low.)

Trump’s evidence for the morality and practicality of a wall? Wealthy politicians build them to protect their homes. Setting aside the question of whether we can accept anything done by a politician as practical or moral evidence, Trump said in his address to the nation: “They don’t build them because they hate the people on the outside, but because they love the people on the inside.”

There you have it. According to Trump, walls are built not to keep people out, but to keep them in. The border wall is less an evidence of Trump’s antipathy for minorities and the poor (which is real), than it is an expression of his isolationism, his nationalism, his nativism.

For Trump, life is a zero-sum game. You are either in or out. And if you are out, we have to exert every effort, spend every dollar, not so much for keeping drugs and immigrants and disease and crime out of our country as for keeping us in. Trump would separate us from the world where, in the security of our walled city on a hill, he can enforce his own brand of terrorism, causing us to fear those who are “the other,” who — in his fetid vision of the world — crowd our walls like the Mongol hordes attempting to scale the Great Wall of China.

(Which they did.)

“Good fences make good neighbors,” the Donald Trump in Robert Frost’s poem argues.

But the poetic argument and the recent evidence is that they don’t. And the wall we are being compelled — by the lethargy of our Congress and the terrorizing threats of our president — to build is less a protection than an indictment: What was once our welcoming “City on a Hill” has become a fortress, an armed encampment against the poor, the suffering, the terrified of whom our president insists we be terrified.

Robert Frost provides the answer we must give to Trump: the wall he insists we build is not a necessity or a priority or a morality, but— for Donald Trump — “just another kind of out-door game.”

And an evil one.

Robert A. Rees

Robert Rees is director of Mormon Studies at Graduate Theological Union in Berkeley, Calif.

Clifton Jolley

Clifton Jolley is a writer and president of Advent Communications, Ogden.