If there's one thing about NAFTA/WTO-style free trade that has always driven labor activists nuts, it's that modern trade agreements allow "free flow of capital" but not "free flow of people." So you'd expect organized labor to support any move that will give workers more flexibility and power, right?

Wrong.

While American labor has come a long way since the 1980s (when the AFL-CIO supported the most punitive "employer sanction" aspects of that era's immigration-reform efforts), the country's major unions do not speak with one voice on this topic. And the complicated labor arguments over immigration indicate more than just divergent motivations among unions. They hint at why even the best "guest worker" legislation will be the kind of half-measure that principled supporters of open immigration should treat with skepticism.

"We remain deeply troubled by the expansion of guest worker programs—for workers not already in this country—contemplated by the bill voted out of the Senate Judiciary Committee," AFL-CIO President John Sweeney announced recently. "Guest workers programs are a bad idea and harm all workers."

Whatever party politics Sweeney may have played in souring the Senate's efforts at a compromise immigration reform bill, he was invoking classical zero-sum labor politics: Freer entry by new workers from south of the border means more competition, and more downward wage pressure, for Sweeney's constituents. Interestingly, however, his is not a unanimous labor position. The Service Employees International Union took the opposite tack, backing the Judiciary Committee bill, and for reasons that mirror Sweeney's reasons for opposing it. SEIU spokesperson Avril Smith says the organization's decision was based on a number of factors, including an expansive guest worker program and the bill's guarantee of 325,000 new work visas per year. "Any legislation we support will have to include visa programs," she says.

If you want to see the kind of philosophical differences that drove SEIU's spectacular divorce from the AFL-CIO last year, this is a pretty good example. The major unions share the view that existing undocumented workers—the 12 million or so reputed to be in the United States today—should be regularized (and made easier to organize). The difference of opinion arises from the proverbial campesino who is still in Mexico but may come north in the future. Is that person a potential ally or a competitor for scarce wages?

SEIU's answer depends partly on the organization's demographic, which is high in immigrant laborers. (Some unions in the "Change to Win" coalition that joined SEIU in splitting from from AFL-CIO have not taken a position on the current round of immigration reform.) But even United Farm Workers of America, which has a largely though not wholly immigrant workforce (despite popular images of the migrant worker as the icon of illegal immigration, only about one million of the reputed 12 million undocumented workers in the United States work in agriculture), is careful to separate its own guest worker efforts from plans that would open up new visa opportunities to people who are not already in the country. UFW's "Ag Jobs" initiative, explains spokesman Marc Grossman, "is not retroactive. You can't come into the country and then take advantage of it… But if they've been brought into this country, we want to protect them."

So where does that leave a Mexican citizen who hopes to make it to the United States someday? "Out of luck," Grossman says.

Considering how much the SEIU and UFW contributed to last week's impressive pro-immigrant demonstrations, it may seem paradoxical to argue that the interests of the unions conflict with the interests of freer immigration. "Most labor unions see that their ranks will be swollen by these people," says Hector Flores, president of the League of United Latin American Citizens. "So you'd be shooting yourself in the foot to say 'I oppose these people.'" But the modest goal of a more functional guest worker program raises problems for a principled supporter of free immigration.

First, as Jesse James DeConto demonstrated in Reason's February issue, even a fully functioning guest worker program creates cruelties for the people who are actually participating in it. More important, there's something paradoxical in allotting visas or guest worker provisions only to people who are tied to employee situations in the United States. Immigrants have always been among the most entrepreneurial classes in American life. You could make the case that small business startups have been the single greatest national benefit of immigration. It's an idiocy worthy of, well, the United States government to make the promise of immigration dependant upon your ability to find a clock-punching job at an already-existing company.

The solution to the immigration crisis, if there is such a crisis, does not rest in guest worker programs or higher visa quotas, but in the one possibility nobody is mentioning: eliminating visas altogether within the NAFTA countries, and allowing Canadians, Americans, and Mexicans with legitimate passports to travel freely among our three countries for any reason or for no reason. This was the early vision of Ronald Reagan, and it was certainly an implied outcome of the North American Free Trade Agreement. "NAFTA had an effect on the Mexican economy, in terms of encouraging campesinos to leave the farm and seek better opportunities," says Fred Tsao, policy director of the Illinois Coalition for Immigrant Rights, "but we've shut off the legal opportunities for people to do that."

The pathetic aspect of this debate is that visaless NAFTA borders would not even be a novel step. They would be a partial return to the way things were in the golden age, when the Tancredos, the Sensenbrenners, and the Cavanaughs first fouled these shores. Anti-illegal-immigrant types who never tire of pointing out that their ancestors came here legally are making a hollow argument: Until fairly recently in American history, there was no motive for illegal immigration; all a prospective American had to do was show up. It's a sign of a timid and tired nation that, in a period of economic expansion, we're not even willing to allow such an open system for our immediate neighbors and closest trading partners. "Guest worker provisions are an attempt to recapture some of the circularity that happened in the past, when people moved more freely between countries," says Tsao. "Whether that's going to work, I don't know."

When asked about visaless borders, every person I interviewed for this article gave two replies: that we need to be realistic about our options, and that the guest-worker compromise will be more fair than what we have now. The first of these answers is half-right: In the current political climate, the idea of eliminating visa requirements with Canada and Mexico seems as heretical as the notion of pasteurization or a sun-centered solar system. Beyond that, the arguments of realism and fairness are entirely wrong. The guest worker compromise is unrealistic because it has nothing to do with economic reality on this continent. Nor is it especially fair: At best it will grandfather in some portion of the existing undocumented workforce (and probably not a very large portion). For anybody who dreams of coming to the United States for a better job, or to start his or her own taqueria or a retail toque outlet, the various current Senate proposals will not increase, and may even reduce, the legal opportunities to pursue the American dream.

Since all parties to this debate draw a line between legal and illegal immigration, we should note that visaless borders would greatly increase the former and virtually eliminate the latter. Is that a problem? I don't think so, and people who oppose the idea need to explain why they think it would be.