For over a century the challenge of immigration has vexed organized labor. In the late nineteenth century, the American Federation of Labor (AFL), led by cigarmaker Samuel Gompers (himself an immigrant from Europe who, in his own words, “secured the honors and duties of citizenship” only in his twenties), entered national politics largely to press for immigration restriction. AFL leaders believed that an influx of immigrant workers could only weaken the bargaining position of American labor. Only over decades, and with great effort, had American workers taught themselves the skills, habits, and discipline necessary to create enduring labor organizations. The AFL worried that a sudden flood of desperate foreign workers from Poland, Italy, and China, with little trade-union background, could easily drown the infant movement. For much of its subsequent history organized labor viewed immigration with alarm.

Many in the chattering classes-whose jobs, at least until recently, were more secure than those of blue-collar workers-have been quick to assume that this fear was based on prejudice. Yet the alarm of American workers has not been without justification. The existence today of a shadow population of 10 or 12 million undocumented workers permanently barred from the rights and obligations of citizenship cannot but complicate workers’ efforts to advance their interests. Any increase in the labor supply tends to reduce the bargaining power of workers.

According to a 2006 Pew Hispanic Center study, approximately 2 million undocumented workers are employed in construction. We in the Laborers Union see how these workers are treated every day. Unscrupulous contractors routinely evade payroll taxes by paying workers under the table-or dodge paying workers altogether by issuing paychecks that bounce. Contractors fire workers who get injured on the job or who complain about working conditions. Undocumented workers are unlikely to file a law suit, or approach the authorities for help, because they fear deportation. Meanwhile, honest contractors willing to pay union wages and benefits are placed in an increasingly untenable competitive position.

Too often those who express concern for the rule of law are dismissed as closet racists. This is unfair, for in a republic like ours-where laws are the outcome of a democratic process-a willing adherence to the law is the core virtue of the citizen. Labor leaders should understand this more than most, for we have seen what happens when the law is disregarded. In not a few cases the same meatpackers or custodial companies that have illegally terrorized workers for seeking union representation have employed undocumented workers. We cannot simply exonerate workers who enter the country illegally while excoriating firms that unlawfully deprive workers of their rights.

Relying on the labor of a population permanently barred from the “honors and duties of citizenship” imperils our laws and institutions. The experience of slavery and Jim Crow should leave Americans with no doubts on this score. For the good of U.S. democracy, the government must either accept undocumented immigrants into society or send them away. The second option would be difficult to conceive. A police operation that would identify and expel 10 or 12 million from our midst would be incompatible with cherished U.S. traditions of liberty. After all, “Are your papers in order?” is a profoundly un-American question. Americans are not prepared to live in a society of police checkpoints, national ID cards, and intrusive questioning about national heritage-nor should they be.

It is clear that the United States needs to find ways to integrate immigrants into society. Undocumented immigrants should be allowed to show their commitment to America and its values-by paying taxes, learning our history, legally contributing to our economy, and participating in community associations from political parties to PTAs. Here is where organized labor can help. Trade unions have a strong history as engines of assimilation for immigrant workers.

In our nation, citizenship is neither an entitlement nor a property of race or language. Instead it is defined by adherence to a set of values enshrined in our political order and way of life. Gompers-who so often led the charge for immigration restriction-believed that labor unions were the “schools of democracy” where immigrant workers learned those values. The AFL president rated a successful 1902 strike in the Eastern Pennsylvania coal mines-by a largely foreign-born work force-as the single most important event in U.S. labor history. It was critical precisely because, in Gompers’s words, “from then on the miners became not merely human machines to produce coal but men and citizens, taking their place among the fairly well-paid, intelligent men, husbands, fathers, abreast of all the people not only of their communities but of the republic.” Decades later the birth of industrial unions like the United Autoworkers and the United Steelworkers enabled millions of once-desperate immigrant workers from Southern and Eastern Europe to raise themselves to be solid, middle-class citizens. These blue-collar white “ethnics”-people who learned their civics lessons on the shop floor and in the union hall-emerged as the solid foundation of America’s great twentieth-century crusades to save democracy from the twin totalitarian challenges of fascism and communism.

My own local union-Laborers Local 11 in Alexandria, Virginia-is a model of outreach to immigrants. In Northern Virginia, where most construction laborers are Latinos born outside the United States, Local 11 has adapted to meet the challenges of a shifting labor force-fighting for immigrants instead of against immigration. Our meetings are conducted primarily in Spanish, with English translation. Since we aspire to represent every worker in our industry, we don’t make invasive inquiries about the immigration status of prospective members (nor does the law require us to do so, as it does for employers). Our apprenticeship program offers training classes in both English and Spanish, and finances English as a Second Language instruction for members. We network with worker centers, church groups, and other immigrant advocates. Our president, Hugo Carballo-a naturalized citizen from El Salvador-has emerged as a leader of the Latino community in Northern Virginia. Our political program, which aims to boost turnout among the surprising number of new Latino citizens who are eligible to vote but do not, is widely respected.

The demographics of the construction trade in Northern Virginia-overwhelmingly Latino and foreign-born-have made this outreach easier for Local 11 than for many other local labor unions, within the Laborers and without. Where the workforce is still deeply divided between immigrant Latinos and native-born whites and/or blacks, internal politics complicate every step. Union workers are not immune from the fears and jealousies that characterize every other segment of our citizenry.

Virginia is one of the nation’s toughest places for workers to organize: we have the nation’s third lowest rate of union membership, and the right of every worker not to join a union is both specifically enshrined in law and celebrated by the state’s politicians. Yet in spite of this notoriously antilabor climate, Laborers Local 11 has tripled its membership in three years to more than five hundred members. This means that nearly five hundred new Americans, by participating in union and community affairs, are learning the elementary skills required of citizens.