In a 20-page report looking at immigration and American agriculture, the White House said farmers are already having trouble recruiting workers, and many are cutting back on what they grow or are moving operations abroad as a result of the labor shortage.
That comes even at a time when the administration says it isn't targeting those rank-and-file illegal immigrants for deportation — something the administration hinted could change, and could harm farms and rural communities.
"Without providing a path to earned citizenship for unauthorized farmworkers and a new temporary program that agriculture employers would use, a significant portion of this farm workforce will remain unauthorized, thereby susceptible to immigration enforcement actions that could tighten the supply of farm labor," the report said.
Numbers are difficult to pinpoint, but the White House said anywhere from 50 percent to 60 percent of farm workers are in the U.S. illegally.
The new report comes as the momentum fades for getting an immigration bill through Congress this year.
A version passed the Senate in June on a bipartisan 68-32 vote, but it is considered dead in the House — and Senate leaders haven't even sent the bill over for consideration.
Meanwhile, House GOP members are sparring over how to proceed, with some arguing they need to pass a bill that includes legalizing most illegal immigrants, while others say they should focus on enforcement.
Republican leaders appear to be preparing the ground for a strategy that would legalize at least some illegal immigrants brought to the U.S. as children.
With many Republicans holding rural districts, Monday's report seemed designed to make an economic argument to entice them to support broad immigration reforms including legalization.
"Under the current system, rural America is losing opportunity and harvests due to lack of a stable workforce," the White House said. "Coupled with a decline in native-born rural populations, the strength and continuity of rural America is contingent on common-sense immigration reform that improves job opportunity, provides local governments with the tools they need to succeed, and increases economic growth."
The Senate bill includes a special pathway to citizenship for farm workers here illegally, giving them the chance to earn a green card in just five years, or half the time of most illegal immigrants.
The Senate legislation would also overhaul the agriculture guest-worker programs, allowing workers to switch between employers and allowing employers to bring in year-round, skilled workers, rather than the seasonal farm hands that the current program was designed for.
The House Judiciary Committee last month cleared its own agriculture guest-worker bill, cutting paperwork and regulations and expanding the program to include non-seasonal work. But the House bill does not include legal status for currently illegal immigrant farm workers.