It’s become a time-honored tradition. Every year for almost a decade, members of Congress—spurred by corporate lobbyists who can’t gather enough support from their fellow colleagues for an immigration policy that will lower wages and degrade working conditions for migrant and American workers—use the appropriations process to get what they want. Few people pay close attention to the deliberations about how to fund the government, so members of Congress can quietly tack their bad idea as a “rider” onto an appropriations bill that is folded into an “omnibus” appropriations bill to keep the government running. If the president vetoes the omnibus budget, the government may shut down. This makes a veto unlikely, which allows riders to become law without facing a debate and vote on the merits of it in the House and Senate.

Appropriations riders have become common in U.S. labor migration policy. President Obama’s attempts to improve wages and working conditions for American and migrant workers in the H-2B guestworker program—for jobs in landscaping, forestry, construction and seafood processing, for example—were thwarted again and again through appropriations riders that lowered minimum wage rates for workers and prohibited the Labor Department from enforcing key rules. Senators Grassley (R-IA) and Feinstein (D-CA) took a bipartisan stand against the practice when it happened again this year. This time around, the rules in the H-2A program—which allows agricultural employers and farmers to hire workers from abroad to fill temporary or seasonal jobs lasting for less than one year—may also be modified via an appropriations rider.

There is no annual limit on the number of H-2A workers that can be hired, and H-2A is the fastest-growing U.S. guestworker program, more than doubling over the past decade, with over 200,000 farm jobs certified in in 2017. The vast majority of H-2A workers are employed on crop farms, picking fruits and vegetables.

The House appropriations committee in charge of funding the Department of Homeland Security (DHS) has now added a rider that would allow H-2A guestworkers to be employed in year-round jobs, thus drastically expanding the scope of this program. By allowing year-round employment, employers could seek to bring in guestworkers for jobs on dairy, livestock, and poultry and egg farms, as well as in nurseries and greenhouses and other non-seasonal agricultural occupations. Next week, the Senate appropriations committee is expected to consider its DHS appropriations bill. If this year-round rider becomes law, there would be a major change in immigration policy, converting the H-2A program from a safety valve for farmers who cannot find enough seasonal workers into a program admitting guestworkers to do year-round, permanent jobs. The H-2A program could radically change in purpose and size without ever being debated in either the House or Senate Judiciary Committees which are responsible for crafting immigration legislation.

This is troubling because H-2A is a guestworker program that has facilitated the exploitation of migrant workers and even human trafficking; so much that it has been dubbed “Close to Slavery” and “The New American Slavery.” Many H-2A workers arrive in debt to labor recruiters who in effect sell them their temporary jobs. They cannot change employers, and become deportable if they are fired by their employers, which keeps them from complaining about unpaid wages and other workplace violations. The title of a recent government audit reflected this reality: “H-2A and H-2B Visa Programs: Increased Protections Needed for Foreign Workers.” It’s also difficult for H-2A workers to bring their families with them and they have no path to permanent residence and citizenship.

The terms and conditions of the program give employers an inordinate amount of power over their workers, as well as other benefits, like being exempt from paying payroll taxes on H-2A workers and the ability to hand-pick workers from abroad by age and gender without being subject to U.S. anti-discrimination laws. Those are major reasons why employers prefer to hire H-2A workers instead of U.S. workers. We know that this is the case because occasionally they get caught discriminating against American workers in favor of H-2A workers.

Despite its poor track record and the repeated warnings of farmworker advocates, the H-2A program has earned bipartisan support in Congress, including from lawmakers who have voiced support for allowing dairies to hire year-round workers via the H-2A program—a long-time goal of dairy farmers—who claim they cannot find enough U.S. workers willing to work on dairies. Many of the current employees on dairies are unauthorized immigrants: the Wisconsin Center for Investigative Journalism and HuffPost called unauthorized immigrants the “Backbone of Dairies.” The combination of a largely undocumented workforce with the Trump administration’s increasing number of arrests of unauthorized immigrants have left dairy farmers seeking an insurance policy against losing their workforce. That’s understandable, but what about the current workforce employed on dairies? The year-round rider will push unauthorized workers into the informal labor market, which will push down wages and labor standards in agriculture. And, of course, making H-2A year-round won’t improve the few protections for migrant workers in the H-2A program, which some members of Congress like Rep. Goodlatte are trying to eliminate through other legislative measures.

The H-2A year-round rider raises two key questions: (1) How many permanent, year-round jobs might be impacted and (2) does it make sense to fill permanent jobs with temporary-and-virtually-indentured guestworkers?

First, most of the year-round agricultural jobs that would be eligible for the H-2A program are in “animal production”, industry code NAICS 112, which includes jobs in cattle ranching and farming, hog and pig farming, dairies, poultry and egg production, sheep and goat farming, and animal aquaculture. (Although there are a handful of other job categories that might be eligible as well). Nearly 260,000 persons were employed in animal production in 2016, an increase of 20 percent from 2006 (see Table 1), including 40 percent who worked in “dairy cattle and milk production” (NAICS 11212), where employment increased by nearly one-third, from 78,618 to 104,377.

If the year-round rider becomes law, ag employers and especially dairy farmers will have a strong incentive to begin replacing their unauthorized workers with H-2A workers because H-2A workers can’t change employers if a competing farm offers a higher wage and they’re safe from deportation by virtue of their nonimmigrant visa. Unfortunately for U.S. workers and other authorized immigrants, ag employers also like the H-2A program because it insulates them from free market forces that would lead them to improve wages and working conditions in order to attract U.S. workers.

If the year-round rider is renewed every year, as may happen if it becomes law this year, ag employers may eventually fill many of the 260,000 jobs in animal production (plus any other eligible job categories) with H-2A workers, increasing the H-2A program to 460,000, approximately the same number of workers admitted through the Bracero guestworker program during its peak in the mid 1950s.

The second question is whether the U.S. government should fill permanent jobs with guestworkers. The seasonal nature of farm jobs is what arguably makes it more difficult to find and retain local workers, but the same argument cannot be made for stable, year-round jobs. That’s why allowing employers to fill permanent jobs in agriculture with guestworkers who have few rights is particularly repugnant. To the extent a bona fide labor shortage exists, employers should first try expanding their search for workers nationwide, and offer higher wages and better working conditions and benefits. The recent publicized reports of dairy workers dying in manure ponds in Iowa serve as a stark reminder that conditions on many farms and dairies are substandard and too often deadly.

But there must also be a recognition that there are already people doing this valuable work, and that many of them are unauthorized immigrants. Rather than seeking to displace these experienced workers with new H-2A workers, Congress should pass legislation giving unauthorized workers the opportunity to earn legal status and continue working without fear of deportation. The Agricultural Worker Program Act, introduced by Sens. Feinstein and Leahy (D-VT), proposes to do just that. If the dairy industry truly needs immigrants to save it, as so many assert, then dairy farmers should support this proposal and let Congress know about it.

If—after legalizing the current workforce—a bona fide labor shortage in agriculture still exists, then why not recruit and hire permanent immigrants rather than guestworkers to fill those jobs? Migrant workers in the United States who fill labor shortages should have an opportunity to fully integrate and become citizens. It’s the bare minimum the country owes them for their contributions to the American labor market.

Rather than looking for ways to expand the H-2A program through arcane and unethical parliamentary tactics, Congress should explore how to reform the H-2A program so that it gives migrant workers equal rights and an eventual path to permanent residence and citizenship.