Can anything be done about illegal immigration?

Donald J. Trump’s proposal to end illegal immigration — to build a supposedly impregnable wall — is a fake solution. For all intents and purposes, the wall is already there: a fence across large stretches of the southwestern border complemented by drones, sensors and a small army of agents.

It has already failed. The federal government spent more than $200 billion in the last 20 years on immigration enforcement. And the population of unauthorized immigrants swelled to 11 million over the period.

Maybe the answer, instead, lies in another direction. Rather than building a bigger wall, it consists of opening a door in the wall we have. The best way to stop illegal immigration, might be for Mexico and the United States to create a legal path for low-skill Mexicans seeking work in the United States.