The U.S. Census Bureau reported Thursday that most people with science, technology, engineering and math backgrounds don’t have jobs in those STEM fields, a statistic that calls into question the arguments of those saying the U.S. needs to import more skilled workers from overseas.

According to new data from Census’s 2012 American Community Survey, STEM graduates have a low unemployment rate, but 74 percent of them aren’t working in a STEM field at all.

Toron Smith, 13, uses a microscope to look at animal hairs while learning about forensic science, at the Coley Little S.T.E.M camp Thursday, July 10, 2014. Companies say they need more STEM workers, but some Republicans say importing workers will take jobs away from Americans. (AP Photo/The Free Press, Janet S. Carter)

Based on data pulled from that survey, just 25 percent of people with science and engineering degrees are working in a related field. Within that broad category, about half of the people with computer, math, statistics and engineering degrees have jobs in related fields, but the number falls sharply for others.

For example, just 15 percent of people with biology, agriculture and environmental sciences degrees are employed in related fields.

The Census data will likely bolster arguments from Republicans who say the U.S. does not desperately need to pass immigration reform in order to bring more STEM graduates to the United States.

High-tech companies like Microsoft and Google disagree, and say that not only do they need workers, but many high-tech companies are being founded in the United States by immigrants. Business groups like the U.S. Chamber of Commerce  also support increased STEM visas, as do many Republicans in Congress.

But members like Sen. Jeff Sessions (R-Ala.) have said there are millions of Americans who are still out of work, and that the government should be focusing on getting them back to work, not making it easier for non-U.S. citizens to work in the country.

Back in May, Sessions criticized an Obama administration plan to create 100,000 guest worker permits for the spouses of foreign STEM workers. Sessions called it a plan that benefits foreign workers over U.S. citizens looking for work.

“It is good news for citizens in other countries who will be hired,” he said. “But for struggling Americans, it will only reduce wages, lower job opportunities, and make it harder to scrape by.”