It is rare in the immigration debate for big business to come together with civil rights groups to challenge the constitutionality of legislation.
But the U.S. Chamber of Commerce has joined groups such as the National Immigration Law Center and the Mexican American Legal Defense Fund in filing suit against the state of Arizona for a law that severely sanctions employers for knowingly hiring illegal immigrants. On Wednesday the Supreme Court will hear arguments in the case.
The groups argue that the Legal Arizona Worker's Act, and similar legislation in other states, unconstitutionally conflict with existing federal law. The legislation is part of an emerging trend, as state lawmakers complain the federal government is not doing enough in its traditional role of immigration regulation.
The United State Justice Department has filed a brief in support of the groups, arguing that the state laws are generating confusion among employers and employees.
"Those provisions," writes Acting Solicitor General Neal Katyal, "disrupt a careful balance that Congress struck nearly 25 years ago between two interests of the highest importance: ensuring that employers do not undermine enforcement of immigration laws by hiring unauthorized workers, while also ensuring that employers do not discriminate against racial and ethnic minorities legally in the country."
In some cases the state law imposes harsher sanctions on employers than under federal law.
Robin Conrad of the Chamber of Commerce says, "American businesses are overwhelmed by the cacophony of complex and often conflicting state and local immigration regulations."
Conrad says that States are frustrated with the "broken immigration system" but that "the confusing patchwork of immigration regulations doesn't solve our immigration problems, and instead makes it more difficult for employers to create jobs and grow the economy."
The law also mandates that employers check the immigration status of potential employees through a federal database called the E-Verify program. Under federal law, however, the use of E-Verify is voluntary.
"Congress made E-Verify voluntary for good reason" writes Carter G. Phillips, a lawyer for the coalition of groups. " It historically has been error-prone, and requires participating employers to weigh possible benefits against serious burdens."
The law was signed in 2007 by Arizona's then-governor, Janet Napolitano. She is now the Secretary of the Department of Homeland Security, which overseas federal immigration.
In court briefs lawyers for Arizona support the law, saying it is an attempt "to ensure that workers who are hired by Arizona employers are legally authorized to work in this country."
The state argues that federal law should not take precedence. " Although the federal government is responsible for regulating immigration, there remains room for State legislation that touches on immigration issues."
The case is being watched carefully as a possible precursor to a challenge to another controversial Arizona law -- the one requiring police to ask for papers from anyone they think might be in the country illegally.
Justice Elena Kagan will not participate in Wednesday's case, having dealt with the issue in her previous role as Solicitor General of the United States.