Senate Judiciary Committee Chairman Chuck Grassley recently reintroduced an E-Verify bill that ought to concern privacy advocates. If enacted, the bill would implement the employment verification scheme nationwide, something President Trump called for during his campaign. Nationwide E-Verify would establish the framework for a national ID system that would undoubtedly come to be used for more than the enforcement of immigration laws.

E-Verify allows employers to check a new hire’s information against government databases to confirm legal status. It is an ineffective system. One reason why E-Verify suffers from inefficiency is because, as things stand, employers taking part in E-Verify use information from documents such as Social Security cards provided by employees. Because the E-Verify system matches employees’ names with a Social Security Number (SSN) it’s possible for an unauthorized worker using a fraudulent SSN to be cleared for employment. A 2009 audit commissioned by the United States Citizenship and Immigration Services estimated that 54 percent of unauthorized workers who submitted documents via E-Verify were erroneously cleared for employment thanks to fraud.

An effective E-Verify system would have to address this glaring loophole. One way of addressing E-Verify’s inadequacy is to include biometric information, such as a facial photograph. Such proposals are worrying.

The E-Verify system currently checks submitted data against Department of Homeland Security (DHS) and Social Security Administration databases. Section 11 of Grassley’s bill would allow the E-Verify system to include the “passport and visa record (including photographs) maintained by the Department of State” as well as driver's license photos. Seven states voluntarily provide DHS with driver's license data as part of the Records and Information from DMVs for E-Verify (RIDE) initiative.

That Grassley’s bill explicitly mentions driver's license photos is important. Allowing the DHS secretary to deem it necessary for the E-Verify system to confirm identity via driver's license photos introduces biometric information that proponents believe will make the system more effective.

If the statute purports to require that 43 states provide DMV information that raises constitutional concerns, but as the recent debates surrounding REAL-ID show, the federal government could try to coerce states into compliance. DHS announced earlier this year that residents in nine states will need an identifying document other than a state driver's license to fly if their licenses are not REAL-ID compliant by January 22, 2018.

Even if the federal government fails to force states to submit DMV data under a nationwide E-Verify scheme, there is still the possibility of nationwide E-Verify leading to a de facto biometric national ID card.

Congress could gather biometric data from residents of states that don’t send DMV data to the federal government by mandating a biometric Social Security card in an attempt to address one of E-Verify’s most prominent flaws. Such a plan has been proposed before.

In 2010 Sens. Charles Schumer (D-NY) and Lindsey Graham (R-SC) took to the pages of The Washington Post, proposing a way to “mend immigration.” They listed mandatory biometric Social Security cards as one of the four pillars of their plan.

If nationwide E-Verify is enforced we should expect such proposals to resurface as states resist DHS requests for their driver's license photos. These proposals would lead to a biometric national ID being required for employment.

Such a biometric ID card will not only be used to enforce immigration law. A mandatory nationwide identity card provides an ideal mechanism for lawmakers wishing to establish a gun registry, something gun rights activists haven’t overlooked. In 2015, the president of the National Association for Gun Rights (NAGR) wrote to supporters, urging them to contact the House Judiciary Committee to register their opposition to Rep. Lamar Smith’s (R-TX) “Legal Workforce Act.” If enacted, the legislation would have mandated E-Verify nationwide.

But it’s not only law abiding gun owners who should fear nationwide E-Verify. A national ID system designed for immigration enforcement will almost certainly be applied in wider law and regulatory enforcement contexts. A national ID could be used to regulate and oversee access to healthcare, medicine, and housing. Such a system would put citizens’ privacy at risk, allowing for increased government monitoring and data collection.

Grassley’s bill is cosponsored by some of his Republican colleagues. Perhaps Grassley and his bill’s cosponsors should consider that many notable members of their party considered national ID schemes anathema to Republican principles. When Attorney General William French Smith proposed a national ID, President Reagan ridiculed the idea saying, “Maybe we should just brand all the babies.” Sen. Barry Goldwater (R-AZ) was also opposed to a national ID system. More recently, Sen. Rand Paul (R-KY) has spoken out against national ID.

Nationwide E-Verify’s costs would vastly outweigh its proclaimed benefits, and would lead to calls for, and implementation of, nationwide biometric ID. Such proposals are a threat to Americans’ privacy and a needless expansion of federal government power.