The history of the world is a story of fences that failed: the Great Wall of China, the Red Sea, the Berlin Wall, Robert McNamara’s electronic wall dividing Vietnam, followed by the horror of Agent Orange. Securing the 2,000 mile border [with Mexico] was expected to cost $7.6B; the estimate will now go up. But desperate people will find a way in spite of obstacles. By contrast, the border with Canada remains unsecured. Why would Canadians want to come here? About 200,000 illegal immigrants enter from Mexico each year. For $7.6B we could pay them $38,000 each to stay in Mexico. We would all be better off.Um, except for the incentive effects, Bob. Still, it's got to be a more productive line of thought than just using the issue to stir up hatred in an effort to elect Republicans.
Curiously, it seems at one point Abraham Lincoln had some similar thoughts about the costs of buying slaves' freedom vs. continuing the Civil War. (H/t Sam Smith)