Less than two months after the US Department of Justice sued Arizona over the state’s controversial immigration law, it has filed another lawsuit targeting immigration practices by Arizona authorities.

The new case is unrelated to the one against Gov. Jan Brewer and the state over the illegal immigration law, but that doesn't mean it won't be a divisive one. Legal experts say it further sets up a clash between the 10th Amendment - which gives to states all powers that aren't explicitly granted to the federal government - and the Supremacy Clause, which gives the federal government exclusive power over immigration.

In the new suit, filed Monday, the Justice Department says Phoenix-area Maricopa Community Colleges (MCC) discriminated against almost 250 noncitizen job applicants by requiring them to fill out more documents than the law requires to prove their eligibility to work.

Monday's suit is “stronger in a way” than the suit against Governor Brewer over the immigration law, because it is more specific, says Jesse Choper of UC Berkeley’s Boalt School of Law.

Congress has stated what it requires for the employment application, “but doesn’t say what states cannot require,” says Mr. Choper. “If the federal government named the requirements and said these are the only ones, this case would be a slam dunk,” he says. “But they didn’t, so now the government has to argue what they intended.”

It’s “unlawful to treat authorized workers differently during the hiring process based on their citizenship status,” said Thomas Perez, assistant attorney general for the Justice Department’s Civil Rights Division, in a statement. The government is “acting now to remedy this pattern or practice of discrimination.”

This new lawsuit indicates that the state of Arizona continues to dominate the immigration debate in the United States, says Catherine Wilson, an immigration expert at Villanova University. “It also tells us that the Obama administration is cracking down on discriminatory hiring practices for noncitizens at the same time [it] faces intense criticism of heightened levels of deportations under its watch - higher than those under Bush.”

Representatives for Maricopa Community Colleges - which operates 10 colleges and two vocational training centers in the Phoenix area - have declined to comment on the suit. But Ms. Wilson says that there is a possibility that the MCC could settle with the government. That happened in a similar case earlier this year, when John Jay College was sued by the Justice Department for bias against noncitizens.

“They put into effect a training program to avoid further criticism of their hiring practices,” says Wilson. “The MCC training might include similarly training their personnel over what are the proper forms to use and how to see that this doesn’t happen again.”