BLIND TO INVISIBLE BORDERS created by invisible men, many Mexicans are flowing northward into a territory that once was their own. Drawn by the hope of a better life, approximately 90 per cent of the illegal immigrants are able-bodied young men without work in Mexico, victims of agricultural mechanization and a wildly expanding population, who are willing to work at menial jobs for longer hours and lower wages than Americans. They are Mexico's discontented: young, ambitious and frustrated. And many of them are crossing the unseen line, undeterred by rivers, mountains, deserts, men, guns or electronic detection devices. Often they arrive to find they are viewed with hostile eyes by Americans and called illegal, alien unwanted. The brown immigrant, like the Eastern European immigrant of an earlier era, provides an easy scapegoat for those frustrated with the high levels of unemployment and human suffering in our own country.

However, in spite of the popular sentiment that favors hoarding America's wealth for Americans, it is almost certain that there will be many more of these unauthorized human beings entering the United States in the coming years. Economic conditions in Mexico are so wretched that the United States looks like the promised land in comparison. The vast majority of Mexico's 63 million people earn less than $20 a month; devaluation of the peso has brought on 30 per cent inflation and "effectively halved the incomes of those fortunate enough to hold jobs," according to The El Paso Times. And there seems to be no prospect of a lessening of these pressure, as experts predict that Mexico's population will double within the next 20 years.

COMBINE THE WIDESPREAD POVERTY of Mexico with the relative affluence of the United States and an open 3000-mile border separating them and the result is and will continue to be a movement of people from south to north. As one observer put it, "The border is a series of doors with no walls in between." Trying to keep poor people from coming into a rich land at the border is like trying to catch minnows in a net with ten-foot tears.

The Immigration and Naturalization Service (INS) has been trying to do just that and more for decades. The INS, in addition to guarding the border, is also responsible for searching out illegal immigrants within the United States and sending them back to Mexico by the truckloads, like human cattle. These illegal inhabitants of the United States, who number between four and twelve million according to INS statistics, live in constant fear of discovery and humiliation.

Members of the border patrol frankly admit that they only apprehend a small fraction of the people entering illegally. And those caught, if determined to become illicit American residents, can try again and again until they make it through the obstacle course set up by the U.S. government.

LAST AUGUST, President Carter delivered a message to Congress suggesting several ways of revising immigration policy. His most dramatic proposal would grant amnesty to illegal aliens who had lived in the United States for seven years or longer and allow them to live, work and bring their families here; those who had lived here less than seven years, but had arrived prior to January 1, 1977 would be permitted to retain their jobs, though they would be denied most social services and the privilege of bringing their families here.

This is a fine and even courageous proposal, especially in light of the isolationist and xenophobic feelings that seem to dominate public opinion, and it is one that should have been advocated and enacted long ago. It would enable people who have lived here, married here and built homes here to cease worrying about being impersonally torn from lives years in the making.

Even more important, it would protect illegal immigrants from exploitation by making them legal. As of now, illegal aliens form a cheap, defenseless pool of workers, unprotected by American labor laws. As Secretary of Labor F. Ray Marshall has written, "Undocumented workers are subject to blackmail of every conceivable sort. If they complain to their employers about their paltry wages and their unsafe working conditions, they run the risk of being turned in by those owners to the INS." Almost slaves now, these people would gain, from Carter's proposal, the rights of American workers.

Finally, as the INS would not need to hunt down illegal immigrants in the country, INS officials would no longer have to insult all Mexican-American citizens by requesting that they prove their citizenship because of the color of their skin.

UNFORTUNATELY, the humane originality of Carter's amnesty proposal does not carry over to his proposed guidelines for future immigration policy. He has not challenged the quotas established in Public Law 94571, the so-called Eilberg bill, which limits Mexican immigration to 20,000 annually. To enforce this limitation, Carter proposes increasing the guard at the border, a measure that has failed miserably in the past to stem significantly the flow of illegal immigration and offers little hope of doing so in the future. As professor of History John Womack '59, an expert in Latin American affairs has said, "It [a larger border patrol] won't stop those people coming."

Carter has also advocated making the hiring of illegal aliens illegal. But H.R. 9531, Carter's legislation, does not provide criminal penalties for hiring aliens, only fines And nothing in the legislation spells out just how the employer is to ascertain the status of his workers. Given the political clout of the employers and the weak provisions of the bill, it is highly unlikely that this proposal would affect the employment of illegal aliens.

THE UNHAPPY FACT is that the illegal immigration problem cannot be solved by placing a few more guards along the border or by asking employers to stop hiring workers without papers. Heavy illegal immigration is a symptom of a more serious problem--the sad state of the Mexican economy. The U.S. economy can only be made to absorb so many millions of poor unemployed from Mexico. This is not to say there is nothing the United States can do to help, but ultimately Mexico will have to solve its own problems. The U.S. government cannot force the Mexican government to spend more money on population control or on jobs programs. And the U.S. certainly cannot tell Mexico to redistribute its land or to change fundamentally the structure of its economic system.

The real problem with Carter's proposal is that it relies on stop-gap measures that fail to address the underlying causes of the illegal immigrant problem. As long as there are millions of impoverished, frustrated Mexicans, there will be illegal immigration. No law can stop that.