Despite the bitter political divide in Congress over the solution to the nation’s illegal-immigration problem, a sensible consensus already exists: our boundaries must be secured and the massive flow of immigrants across the Mexican-U.S. border regulated, while at the same time a path to citizenship must be made available to the more than 11 million undocumented aliens already in the country.

How to police the border and what steps illegal immigrants should be required to take to qualify for citizenship are rightfully matters of debate and eventual political compromise. What should be rejected out of hand, however, is the call for mass deportation of those here illegally. Regaining control of immigration does not necessitate turning the United States into a virtual police state.

Despite his problematic proposals for a guest-worker program, technological quick fixes, and deployment of the National Guard, President George W. Bush fortunately sought to steer a middle course on this issue in his speech last month. The president’s own party (especially House Republicans) is having none of it, however. The draconian bill passed by the House in December calls for mass deportations, the militarization of the U.S.-Mexican border, and the prosecution of those—even social workers—who assist illegal immigrants. The House bill is shameful political posturing, as unworkable as it is inflammatory. Thanks to warnings from Hispanic legislators, to massive protest rallies, and to the words of religious leaders like Cardinal Roger Mahony of Los Angeles, the House bill has almost no chance of becoming law. Unfortunately, however, political polarization may also mean that no immigration reform at all emerges from this Congress.

Each year half a million immigrants, mostly Hispanics, enter this country illegally. The social, economic, and political consequences are enormous, especially in the handful of border states. U.S. immigration policy should be generous and flexible, but it cannot be left solely to the immigrants themselves. There is, after all, a question of fairness, both to those who enter the country legally and to the hundreds of thousands of would-be immigrants, from Asia, Africa, and elsewhere, who cannot simply cross into the United States.

To be sure, most of the blame for the current crisis lies with U.S. employers, not with those seeking a better life. The demand for low-paid, largely unskilled workers, especially in agriculture and the service industries, is enormous. Like the illegal immigrants themselves, U.S. businesses and consumers turn a blind eye to the niceties of the law. No immigration law will work unless and until employers are penalized for hiring undocumented workers. Where there is a job waiting, people will find a way to cross the border. At the moment, it is not clear that Congress has the will to impose serious penalties against businesses that benefit from illegal immigration. Issuing immigration documents that cannot be easily forged is another serious problem. Still, the bill cosponsored by Edward Kennedy and John McCain now being debated in the Senate is a step in the right direction.

At the same time, the United States needs to work with the Mexican government to improve economic conditions south of the border. As long as poverty and unemployment are endemic in Mexico and other Latin American countries, people will move north. The Economist (April 1) has wisely suggested that the United States subsidize the development of roads and train lines in southern Mexico, where poor infrastructure continues to impede development.

The U.S. Catholic bishops have been vigorous in their support of the illegal-immigrant community. The hierarchy has lobbied for immigrant rights, and in April and May priests, bishops, and lay Catholics demonstrated on behalf of immigration reform. Cardinal Mahony has been rebuked for taking sides in a “political” fight, but he deserves credit for calling the nation’s attention to the potentially disastrous legislation passed by the House.

Lawmakers must balance the good of all citizens against the laudable desire to welcome the needy stranger. The plight of immigrants presents a special dilemma to American Catholics. As descendants of immigrant communities that were often met with hostility by native-born Americans, our instinct is to welcome the next generation of “tired” and “poor” to our shores. Yet the United States simply cannot accommodate all who would migrate here. Immigration will remain crucial to American identity and to our economy, but porous borders offer only a false promise of prosperity and stability. As history shows, assimilating new groups into American society takes time, and time now should be taken to assimilate those already here. Successful assimilation, history also tells us, will strengthen the nation’s commitment to keeping its doors open for future immigrants.

May 23, 2006