On May 26, 2010 the Supreme Court decided 5-to-3 that states can punish employers who violate a mandatory E-Verify law. The court challenge was led by the U.S. Chamber of Congress against Arizona's 2007 law that suspends a business's license if they don't use E-Verify to check the eligibility of all new hires.

NumbersUSA Vice President, Governmental Relations Rosemary Jenks compiled several quotes from the majority opinion written by Chief Justice Roberts. These quotes show the Supreme Court's approval of the Arizona immigration law, and E-Verify. 

From the majority opinion written by Chief Justice Roberts:

Arizona’s licensing law falls well within the confines of the authority Congress chose to leave to the States and therefore is not expressly preempted. While IRCA prohibits States from imposing “civil or criminal sanctions” on those who employ unauthorized aliens, it preserves state authority to impose sanctions “through licensing and similar laws.  (p. 2)
The Chamber and the United States as amicus argue that the Arizona law is not a “licensing” law because it operates only to suspend and revoke licenses rather than to grant them. Again, this construction of the term runs contrary to the definition that Congress itself has codified...It is also contrary to common sense. There is no basis in law, fact, or logic for deeming a law that grants licenses a licensing law, but a law that suspends or revokes those very licenses something else altogether.  (p. 15)
It should not be surprising that the two dissents have sharply different views on how to read the statute. That is the sort of thing that can happen when statutory analysis is so untethered from the text.  (Footnote 6, p. 19)
At its broadest, the Chamber’s argument is that Congress intended the federal system to be exclusive. But Arizona’s procedures simply implement the sanctions that Congress expressly allowed the States to pursue through licensing laws. Given that Congress specifically preserved such authority for the States, it stands to reason that Congress did not intend to prevent the States from using appropriate tools to exercise that authority.  (p. 19)
Apart from the mechanics of the Arizona law, the Chamber argues more generally that the law is preempted because it upsets the balance that Congress sought to strike when enacting IRCA. In the Chamber’s view, IRCA reflects Congress’s careful balancing of several policy considerations—deterring unauthorized alien employment, avoiding burdens on employers, protecting employee privacy, and guarding against employment discrimination. According to the Chamber, the harshness of Arizona’s law “‘exert[s] an extraneous pull on the scheme established byCongress’” that impermissibly upsets that balance....The Chamber and JUSTICE BREYER assert that employers will err on the side of discrimination rather than risk the “‘business death penalty’” by “hiring unauthorized workers.” ...That is not the choice...The Arizona law covers only knowing or intentional violations. The law’s permanent licensing sanctions do not come into play until a second knowing or intentional violation at the same business location, and only if the second violation occurs while the employer is still on probation for the first. These limits ensure that licensing sanctions are imposed only when an employer’s conduct fully justifies them. An employer acting in good faith need have no fear of the sanctions....Other federal laws, and Arizona anti-discrimination laws, provide further protection against employment discrimination—and strong incentive for employers not to discriminate....All that is required to avoid sanctions under the Legal Arizona Workers Act is to refrain from knowingly or intentionally violating the employment law. Employers enjoy safe harbors from liability when they use the I–9 system and E-Verify—as Arizona law requires them to do. The most rational path for employers is to obey the law—both the law barring the employment of unauthorized aliens and the law prohibiting discrimination—and there is no reason to suppose that Arizona employers will choose not to do so....The balancing process that culminated in IRCA resulted in a ban on hiring unauthorized aliens, and the state law here simply seeks to enforce that ban. (pp. 22-26)
In the Chamber’s view, “Congress wanted to develop a reliable and non-burdensome system of work-authorization verification” that could serve as an alternative to the I–9 procedures, and the “mandatory use of E-Verify impedes that purpose.” ....Arizona’s use of E-Verify does not conflict with the federal scheme....In fact, the Federal Government has consistently expanded and encouraged the use of E-Verify.  (pp. 27-28)
The Chamber contends that “if the 49 other States followed Arizona’s lead, the state-mandated drain on federal resources would overwhelm the federal system and render it completely ineffective, thereby defeating Congress’s primary objective in establishing E-Verify.” ...Whatever the legal significance of that argument, the United States does not agree with the factual premise. According to the Department of Homeland Security, “the E-Verify system can accommodate the increased use that the Arizona statute and existing similar laws would create.”  (p. 29)
The Chamber has reservations about E-Verify’s reliability...but again the United States disagrees. The Federal Government reports that “E-Verify’s successful track record . . . is borne out by findings documenting the system’s accuracy and participants’ satisfaction.”  (p. 29)
IRCA expressly reserves to the States the authority to impose sanctions on employers hiring unauthorized workers, through licensing and similar laws. In exercising that authority, Arizona has taken the route least likely to cause tension with federal law. It uses the Federal Government’s own definition of “unauthorized alien,” it relies solely on the Federal Government’s own determination of who is an unauthorized alien, and it requires Arizona employers to use the Federal Government’s own system for checking employee status. If even this gives rise to impermissible conflicts with federal law, then there really is no way for the State to implement licensing sanctions, contrary to the express terms of the savings clause.  (p. 30)
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