The immigration debate is always controversial, but it looks like immigrants might be the best shot the United States has for being a force in the evolving global economy. Cynthia Tucker writes in her new column, “Prosperous American Future Depends On Influx Of Immigrants”:

Sometime last week, demographers estimate, a baby was born who brought the planet’s population to a staggering 7 billion. That’s worrisome, given the stresses on precious resources such as water. But the underlying trend that has created a crowded planet is not a baby boom in distant, impoverished countries. It’s a phenomenon you can see in your own neighborhood or church or civic club: People are living longer and healthier lives.

As someone who hopes to live to an advanced old age, I can hardly denounce the trend. But we’ll face a slew of challenges — including inevitable economic decline — if there are not enough younger workers to fill the coffers for Social Security and Medicare, to feed and bathe and medicate nursing home patients, to build the elderly-equipped housing and drive the wheelchair-accessible vans we’ll need.

The United States has a big advantage over several other nations — if we don’t blow it: We have immigrants, some legal, many illegal, who help to keep our population younger. While native-born American women have more children than their counterparts in Japan and Italy and Greece, it’s also true that workers from Mexico, Guatemala, Colombia and other points south have boosted the U.S. fertility rate.

So here’s something you won’t hear from politicians anywhere on the political spectrum: Let’s celebrate those so-called anchor babies, supposedly born to women who sneak into this country just to confer citizenship on their infants. (That particular right-wing cliche is not borne out by research, but it retains its popularity. If it were true, it would be worth encouraging.)