What Frost rails against is a wall where one is not needed — i.e., where there is no livestock.

He is all pine and I am apple-orchard.
My apple trees will never get across
And eat the cones under his pines, I tell him.

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.

As near as I can read the poem, Frost completely misses the other reason for walls — as ancient boundary markers, which are clearly supported by Scripture. Or perhaps this is his point. Maybe he is railing against private ownership of land? I don’t know enough to make a determination about this.

Frost’s poem describes two neighbors cooperatively mending a wall in a time-honored annual ritual. But the modern example is a case of a neighbor who zealously builds up the wall on one side of his property while all but actively tearing down the wall on the opposite side of his field. Which would you rather be, a Guatemalan apprehended without papers in Chiapas or Oaxaca — or a Mexican similarly apprehended in California or Oregon?

At the borders between modern nation-states, the neighborly cooperation Frost describes is rendered in the form of passports and visas. This is universally recognized as passports are inspected at borders or airports — whether those airports be named for Benito Juarez, Miguel Hidalgo or Kingsford Smith.

I happen to believe that the levels of legal migration into the US are rediculously low (and I believe it can be objectively demonstrated that they are at historically low levels). This is not a good thing. But illegal immigration is the direct cause for these rediculously low levels of legal migration. First, a poorly controlled border means that illegal migration, despite all of its dangers, appears more straightforward than the legal alternative. Second, a large population of illegal immigrants eliminates the desire for higher and more reasonable limits on legal migration.

Years ago, the very night of my arrival in Mexico, I sat at a pastor’s kitchen table when a group of young men from the flock came by to ask for prayer before the left to cross the Rio Bravo. I took it all in stride. They were apprehended and one of these young men became my close companion. At the time of my departure a month later, he publicly thanked God that he had not made it across the border.

Then a few months later, I was telling the story to friend who challenged my thinking. She had also challenged me to rethink the appropriateness of using a scheme I had for riding the BART under the bay but only paying the fare for riding between adjacent East Bay stations.

The lesson I learned was this: the economic benefit and the possiblity of success do not by themselves determine the rightness of a course of action.

So I say, build the fence. Build it soon. It is the first step toward getting higher limits on legal migration.