Donald Trump’s immigration agenda is pushing the Republican debate well to the right and raising concerns in the agribusiness sector, according to an Agri-Pulse report. Much of the debate since Trump’s campaign posted his proposals has focused on his calls to end birthright citizenship and to force Mexico to pay for completing a border wall, while his proposal to make E-Verify mandatory nationwide has been portrayed in the media, and among Republican pundits as a no-brainer and  a requirement that could be imposed relatively painlessly.

But mandatory E-Verify has potentially far-reaching implications for agriculture because of its heavy reliance on workers who would likely be flagged as ineligible to work. So far, farm group lobbyists have been able to keep mandatory E-Verify legislation bottled up in the House. An E-Verify bill has not gone anywhere since it emerged from the Judiciary Committee in March. But fending off such bills will be a lot harder if a Republican wins the White House running on a platform that includes mandatory E-Verify.

Frank Gasperini, executive vice president of the National Council of Agricultural Employers, estimates that making E-Verify checks mandatory would cost agriculture as much as half of its workforce. It might be sufficient for filing an employment documentation form called an I-9, but it is presumed that using E-Verify would expose the documentation as false. For an industry where labor shortages can reach 20 percent, the losses from E-Verify “would be disastrous,” Gasperini said.

Some farmers could presumably make up some of the losses by using the H-2A visa program to import temporary workers legally — there is no cap on the number of visas — but that would not help dairy producers and others who need year-round labor, Gasperini said. And while there are proposals to expand visa programs for low-skill workers, it would take years for the government to ramp them up. E-Verify “might bolster economies in places like Canada, Mexico, and China, but it would be a disaster here,” says Craig Regelbrugge of AmericanHort, the horticultural trade group, alluding to the impact it would have on domestic production.

Neurosurgeon Ben Carson, who is running second in recent Iowa polls, said he would consider military drone strikes on the border. Former Pennsylvania Senator Rick Santorum suggested suspending authorization for Mexican border crossings. Meanwhile, candidates, who are the friendliest to agricultural labor concerns, such as former Florida Gov. Jeb Bush, are struggling to gain any traction. Florida Senator Marco Rubio, who angered conservatives by helping negotiate a bipartisan immigration bill in September, said at the Iowa State Fair that he is still open to providing some kind of legal status to illegal immigrants, but only after a “long time has passed.” “We can’t do that until we prove to Americans that illegal immigration” is under control, Rubio said.