The Trump administration’s harsh enforcement tactics and human rights violations at the border have rightly gotten most of the attention in press coverage about immigration lately, and enforcement has been the basis for the very few questions that Democratic presidential candidates have been asked about immigration so far in the primary debates. What’s gotten less attention and no discussion after five Democratic primary debates are the 17% of workers in the U.S. labor force who are foreign-born, including the 5% of the workforce who are vulnerable to wage theft and other abuses because they lack an immigration status, or the 1% who have an immigration status that is mostly owned and controlled by their employer, by virtue of being employed through U.S. temporary work visa programs.

Only a miniscule number of mentions have been made in the candidates’ published immigration plans about the intersection of immigration and the labor market, and there’s been no discussion on the debate stages about what the Democratic candidates would propose to reform future U.S. labor migration—i.e., migration for the purpose of work. In the past this has sometimes been referred to as “future flows” of migrants: the pathways available to persons from abroad who want to come to the United States to be employed, or avenues for employers that wish to hire migrants, either through temporary work visa programs or as permanent immigrants.

The fifth Democratic Presidential Primary Debate on November 20 was no different than the past four: virtually no discussion of immigration in general—with only one narrow question about the border wall—and no discussion at all about labor migration. Will this change during the sixth debate in December? I hope so, because a positive vision of U.S. labor migration that is fair to immigrants and Americans and fosters solidarity—rather than a corporate-driven race to the bottom on wages and labor standards, which employer groups often push for—is something worth talking about and an argument that progressives can win.

Migrants in the United States are living and working during a time when the president in office clearly doesn’t value their contributions, but nevertheless benefits economically from their labor: President Trump has hired undocumented workers at his companies—some of whom have alleged they were exploited—as well as guestworkers with temporary visas in programs he has expanded, where migrant workers are tied to employers and often underpaid—all while demonizing and scapegoating migrants as criminals and rapists. For the most part, President Trump has gotten a pass on his blatant hypocrisy.

By failing to bring up labor migration issues, the Democratic presidential candidates have not managed to expose Trump’s glaring weakness on the issue. While a significant share of the blame for not discussing the topic at the debates falls at the feet of the moderators, the candidates are making a mistake by not mentioning the contributions that migrant workers make or the challenges they face in the workplace. The candidates also haven’t offered many details about how they would re-make the immigration system so that future migrant workers can enter the U.S. labor market with equal rights and fair pay in their plans for immigration that are published on their campaign websites. A quick summary of what’s included in the immigration plans of a few of the major candidates makes this abundantly clear.

Former Vice President Joe Biden, the leading candidate in some polls, has no dedicated immigration plan, only a single paragraph with general language about fixing the broken immigration system. Mayor Pete Buttigieg’s plan is very vague, mentioning only the need to “modernize our immigration laws to reflect today’s humanitarian and economic needs” with no additional explanation. Senator Kamala Harris, who hails from California—the state hosting the most immigrants—and who just received an endorsement from the United Farm Workers, makes no mention of the connection between immigration and employment on her immigration issue page. Senator Cory Booker’s immigration plan also makes no mention about this whatsoever.

Andrew Yang’s plan is comprised of three paragraphs with a bizarre title that display a misunderstanding of high-skilled immigration in the United States. The Yang proposal is singularly focused on how to “entice high-skill individuals” to come and work in the United States. It notes how “high-skill workers are enticed by high salaries and great benefits,” and proposes to “greatly expand our H-1B and F-1 [student visa] programs” so that more skilled people will be enticed to work and study in the United States. While there’s no question that skilled migration benefits the United States, the plan fails to acknowledge the fact that the H-1B program—for temporary migrant workers with college degrees—is in desperate need of reform, that H-1B workers are usually paid less than the going rate for jobs in the areas where they’re located, and that most employers of H-1B workers use the visa to hire entry-level information technology workers, and sometimes to replace U.S. workers, as Disney, Southern California Edison, and numerous other employers have done.

Julián Castro’s immigration plan offers slightly more, with a good paragraph with general language on the importance of labor protections for migrants hired with temporary visas, allowing their spouses to work, and legalizing undocumented farmworkers.

Two of the candidates, Senators Elizabeth Warren and Bernie Sanders, do offer more details that evidence an understanding of the issue. Warren’s plan has a paragraph that clearly states her desire to “expand legal immigration.” The plan signals that she believes in a few important principles—making the immigration system more transparent and data driven, identifying true needs in the labor market before hiring migrant workers, and including worker voice in the labor migration system. The plan does not however, identify specific changes or proposals that she thinks are necessary to achieve those goals and reform the system.

Senator Bernie Sanders’ plan offers the most details by far when it comes to protecting migrant workers and U.S.-born workers. His plan, in a section titled “Protect and Strengthen Immigrant Labor Rights” specifically calls out employers who take advantage of the immigration system in order to profit from degrading labor standards for unauthorized immigrants and guestworkers in temporary work visa programs, and specifically mentions President Trump’s hypocrisy when it comes to demonizing immigrants for political gain while employing them in low-wage jobs them for his own personal enrichment.

Sanders’ plan would end the workplace raids carried out by U.S. Immigration and Customs Enforcement that do nothing to improve labor standards and create a whistleblower visa so that migrant workers could report workplace violations without fear of deportation; both would increase bargaining power for all workers by diminishing the ability of employers to retaliate against migrant workers with threats related to immigration status. The plan also highlights the fact that the U.S. government spends 11 times more on immigration enforcement than it does on protecting labor standards and pledges to redirect that money to labor enforcement, and promises to end labor standards exemptions for agricultural and domestic workers, many of whom are immigrants.

Some of the plan’s proposals would likely benefit more U.S. workers than migrant workers: Reducing line speed rules at meat processing plants, increasing funding for the Occupational Safety and Health Administration, and pushing to pass the Workplace Democracy Act to combat employers that illegally misclassify workers as independent contractors.

Overall, the Sanders plan smartly focuses on policies that would improve labor standards for all workers—and the benefits of those policies would redound most to low-wage workers in the United States—the same workers whom employers steal billions in wages from every year, and who die or suffer injuries unnecessarily while on the job.

Finally, when it comes to future flows, the Sanders plan is the only one that offers meaningful specificity. Most importantly, Sanders would make temporary work visas portable, so that workers could switch jobs rather than be tied to one employer—a key part of the programs that facilitate exploitation and even human trafficking—and make workers able to petition for their own visa in order to remove the labor recruiter middlemen that take money from migrant workers, usually illegally, as the price of connecting them to U.S. jobs.

It is difficult to believe that in a Democratic presidential primary, only one candidate so far—Bernie Sanders—has demonstrated that they see through and understand the corporate power issues at play in U.S. labor migration governance, and has specific proposals to improve conditions for all workers, regardless of their immigration status.

Meanwhile, soon after assuming the presidency, Trump directed a team of officials in the White House to devise a plan to remake the U.S. immigration system into one that is more “merit-based,” meaning one where the share of immigrant visas are tilted more towards labor migration and away from family reunification, and that prioritizes highly-educated migrants. This is a bad idea because the United States should have an immigration system that continues to reflect the values of family reunification and adequately fulfills our humanitarian obligations, and that is flexible enough to adjust to the skill mix and levels of labor migration that the United States needs at a given point in time, depending on the health of the economy and according to labor market needs.

Therefore, the idea of merit-based immigration shouldn’t be difficult to argue against, but if most Democrats remain silent about labor migration, they will cede the debate to Trump and his supporters in the business community who view immigrants as widgets they can use to fill alleged labor shortages while controlling and underpaying them—and then send them home when their visas expire or when they complain about wages and working conditions.

The Democratic candidates therefore need to offer more details in their plans and on the campaign trail about their vision for the immigration system and the reforms they will push to enact if they win the presidency. Immigration was candidate Trump’s signature issue in the 2016 campaign, and there’s no reason to believe that President Trump won’t use it again during the 2020 general election campaign. Hopefully the moderators at next Democratic debates will begin to realize this and push the candidates to offer more substance.

I urge the moderators at the next Democratic debates to ask at least a few probing questions that allow the public to gauge how well the candidates might fare against President Trump in the general election when discussing migrant workers and the future of U.S. labor migration. Questions like: What would your administration do to ensure that everyone in the labor market, regardless of immigration status, is treated fairly and protected from retaliation in the workplace? Would you end worksite raids? Would you support an increase in the annual cap for U visas that are available to immigrant victims of certain qualifying crimes who are cooperating in a related investigation or prosecution—and expand the crimes to include labor violations? Would you support transitioning away from and replacing temporary work visa programs with ones that offer permanent immigrant visas, so that migrant workers will no longer be indentured to employers and can become permanent residents and eventually citizens?

Note: This post has been updated and was originally published with the title “Will Democrats finally start talking about migrant workers and labor migration at tonight’s debate?”