Slate's Matt Yglesias - known around here as Tom Friedman Jr. - offers "How Come Nobody Thinks Stopping People From Moving To Chicago Would Create Jobs?" ( peekURL.com/zEbLJcf ):

...If a new freeway spur gets built out to a town, nobody says "more people will move here thanks to improved transportation access and joblessness will skyrocket." If more people move to town, that means more investment in residential and commercial structures and more employment in the locally focused services (health, education, retail, food service) that provide most of the employment.

Now obviously this isn't a totally universal principle. If a serial killer moves to town, that's bad news. But a law-abiding person who's come to town to do a job? That's a good thing, unless he's specifically competing with your exact set of skills. Fostering and encouraging the migration of a diverse set of people with diverse skills and aptitudes is only going to add to the wealth and power of the nation.

1. Who Yglesias means by "nobody" is similar to Pauline Kael's definition: those in his circle of very low level elitists and including several libertarians. They're pro-high immigration, so of course they aren't going to say anything against yet more high immigration.

2. Others might wonder what happens after the boom times end. Freeway spurs are generally built as the terminus is booming, but what happens when things slow down? That's when you get the joblessness. For examples, see Flint and Detroit, Gary Indiana, and so on. The same people who helped screw industries in those cities through globalism now support mass immigration.

3. What Yglesias won't acknowledge or will just hand-wave away are the cases that are much less of a strawman than immigration by serial killers. Massive foreign immigration has a negative impact on our need to communicate with one another about vital issues and has helped politicians speak out of both (or more) sides of their mouths. That has a cost, but oddly enough Yglesias isn't weighing it against "the wealth and power of the nation". Nor is he factoring in the political costs of massive immigration: diluting the voting power of the native-born, giving ethnic demagogues a power base, and giving foreign governments in some cases a great deal of political power inside the U.S.

All that and more, Yglesias willfully chooses to ignore. Ask him why: @MattYglesias