01:00 AM EST on Monday, February 28, 2005

The Rio Grande Valley, where Texas meets Mexico, is the poorest region in the United States, yet people clamor to live there. The thing is, most of the people moving in aren't Americans but Mexicans -- many in the United States illegally. While much is made of the benefits that this low-wage labor brings to employers, little is said about its costs to society.

Illegal immigration is no free lunch, and it's time we had an honest discussion of the matter.

Regulating who lives and works in the United States is a federal responsibility. The costs of failure to regulate end up with the state and local governments. Communities across America struggle with the expense of providing hospital care to illegal immigrants and school for their children. For the border states, these burdens weigh heavily.

In Texas, for example, the number of illegal residents has jumped 17 percent since 1996, to an estimated 1.2 million. The closer you get to the border, the crazier the situation becomes. Four of America's 10 poorest metropolitan regions lie along the Texas-Mexico border.

Brownsville, for example, is a stroll across a bridge from Matamoros, Mexico. The population of the once sleepy Texas town grew 41 percent in the 1990s and continues to explode. An amazing 40 percent of the total is under age 19. Imagine a city of only 140,000 trying to support a school system with 40,000 students!

Some 400,000 people live in what are called colonias along the border in Texas. These unincorporated shantytowns often lack water, sewer systems, electricity and paved roads. The colonias residents pay little if any taxes but use the schools and other public services.

Brownsville is the poorest medium-sized American city; a third of its families live in poverty, according to federal guidelines. It's important to recognize that the illegal residents don't just add to the numbers of poor; they also bring down the wages and economic opportunities of the legal residents.

While America's problems caused by illegal immigration are most evident at the Mexican border, the solution lies elsewhere. No number of U.S. Border Patrol jeeps can stop the flow of poor people seeking jobs in the United States. Only penalties for the U.S. employers can do this.

For once illegal immigrants get past the border, Washington does almost nothing to stand between them and American jobs. There's a law requiring the federal government to fine employers who hire illegal immigrants, but the Bush administration has rarely enforced it.

A serious effort to penalize law-breaking American employers would end the problem immediately.

Meanwhile, with jobs drawing undocumented workers to the United States, pressure is lessened on the often corrupt political and economic leaders of their home countries to improve the lot of the people there.

If America needs more foreign workers than legal limits allow, then the policy should be to expand legal immigration. But because the administration, Congress and federal agencies seem to wink at illegal immigration, a class of workers is developing that is underpaid and also hurts the economic prospects of all low-skilled workers. This result may please some employers, but it is not good for those Americans who must compete with illegal immigrants, or for all Americans who pay taxes to support them.

For the states that must deal with large illegal-immigrant populations, the collapse of federal responsibility has created a growing crisis. If the Bush administration won't do its job, Congress should force it to. Or perhaps the politicians in Washington would like to start sending the states big checks to cover the costs of their failure to regulate immigration.