Anti-illegal immigration activists hailed the ruling by U.S. District Judge E. Richard Webber as giving a green light to municipalities nationwide to enact laws targeting illegal immigrants.
Opponents of local efforts say the issue is far from settled, noting that in a nearly identical case, a federal judge in Pennsylvania forbade the city of Hazleton from cracking down on illegal immigrants.
"This is a landscape characterized by significant legal uncertainty and these questions are going to glide their way up through courts," said Peter Spiro, who teaches immigration law at Temple University. "It certainly won't be the last word."
In the Missouri case, Webber upheld an ordinance in the St.
Louis suburb of Valley Park that penalizes businesses that hire illegal immigrants. The judge rejected the American Civil Liberties Union's argument that the law discriminates against Hispanics and tramples on the federal government's exclusive power to regulate immigration.
The ordinance "is not pre-empted by federal law, to the contrary, federal law specifically permits such licensing laws as the one at issue," Webber wrote.
Webber's colleague in Pennsylvania came to a radically different conclusion last summer, striking down the Hazleton law as unconstitutional and saying the city had no business taking on what he called a federal responsibility.
Hazleton's measure, approved in 2006 and challenged by the ACLU, would have denied business permits to companies that employ illegal immigrants, fined landlords who rent to them and required tenants to register and pay for a rental permit.
"Whatever frustrations officials of the city of Hazleton may feel about the current state of federal immigration enforcement, the nature of the political system in the United States prohibits the city from enacting ordinances that disrupt a carefully drawn federal statutory scheme," U.S. District Judge James Munley wrote.
In his opinion, issued six months after Munley's, Webber noted he was free to depart from the ruling in the Hazleton case.
"The Court respectfully notes that the Pennsylvania decision is not binding, and therefore, the Court will conduct its own thorough analysis of the issues presented," he wrote.
Hazleton has appealed Munley's ruling to the 3rd U.S. Circuit Court of Appeals in Philadelphia. The city's lawyers plan to file a brief with the court on Thursday arguing that Munley erred in his interpretation of federal law - and citing Webber's decision in the Valley Park case.
"Judge Webber's reasoning is painstakingly careful and detailed," said Kris Kobach, who represents both Hazleton and Valley Park. "In many ways the opinion is written to persuade not only the parties, but to persuade an appellate court that it is the right interpretation of the law."
But Omar Jadwat, an ACLU attorney who fought both ordinances, predicted Webber's decision will not be as influential with the court as Munley's.
"It's plain the Valley Park decision is a real outlier," he said. "Increasingly, municipalities have seen that these laws are not the right way to go, because they have serious legal flaws and because they are really counterproductive and unhelpful and don't get at whatever problems they actually have."
Hazleton's ordinance was based on a model provided by the Immigration Reform Law Institute, which favors limits on immigration and is affiliated with the Federation for American Immigration Reform.
Inspired by the Hazleton crackdown, dozens of local governments, including the one in Valley Park, passed similar measures that seek to curtail illegal immigration.
