Most Americans understand the need for low-skilled labor in the U.S. and said they supported a visa program for “physically demanding work” for legal immigrants. However, most people did not know that such work visas are in short supply, according to polling that ImmigrationWorks USA published online Tuesday. Researchers found that 78 percent of respondents held a favorable view of legal immigration, and nearly 60 percent of them said they thought the U.S. benefited from and needed legal immigrants to do labor with little or no training involved.

Under current U.S. immigration policy, few visas are made available to immigrants for low-skilled occupations, including those in agriculture, construction and certain hospitality services. The U.S. government caps the only permanent, year-round visa for low-skilled workers at 5,000 annually, according to the Migration Policy Institute. The result has been that employers have often hired unauthorized workers in large numbers to do jobs that often require large amounts of physical labor.

The U.S. employs an estimated 8.4 million undocumented immigrants. Some segments of the economy, like agriculture, are almost entirely dependent upon unauthorized labor, according to the Hill.

ImmigrationWorks USA found that 86 percent of people polled said legal immigrants made an important contribution to the U.S. economy, and the same percent said issuing more work visas for low-skilled jobs would allow immigrants to pay taxes. Respondents were twice as likely to say they understood that the jobs immigrants were taking were not jobs Americans wanted, as opposed to taking jobs away from American workers.

Researchers also discovered that the majority of respondents harbored negative feelings toward undocumented immigrants and often confused questions about legal immigration with the debate over illegal immigration. “We repeatedly needed to remind participants who we were talking about and redirect the discussion back to legal immigration,” researchers noted.

The poll also highlighted some Americans’ misperceptions about legal immigration. For instance, one in two respondents said they thought the U.S. already had a system for immigrants to obtain work visas for low-skilled occupations.

Other recent polling found that Americans are sharply divided on the topic of U.S. immigration reform along party lines. Roughly 83 percent of Iowa Democrats said the U.S. should give undocumented immigrants living in the U.S. a chance to apply for permanent residency, as opposed to just 34 percent of Republicans.