The Department of Justice filed a lawsuit today challenging Arizona's new immigration law, which takes effect July 29.
The suit challenges the law on the grounds that immigration is under the purview of the federal government and that Arizona has overstepped its bounds. Justice also claims that the law is too broad and could result in racial profiling and discrimination.
The lawsuit names Arizona and state Gov. Janice Brewer as the defendants.
While the legal challenge had been expected, signaled by Attorney General Eric Holder and President Barack Obama in statements soon after the statute was enacted, the lawsuit is sure to set off a firestorm of debate pitting the federal government against Arizona.
Republican leaders have already lashed out at the Obama administration.
On ABC News' This Week Sunday, Sen. John McCain, R-Ariz., said, "I invite the president to come to the border, and he can see for himself the absolute necessity of getting our border secure before more violence spills over onto our side of the border."
Arizona State Sen. Russell Pearce, a Republican who was the principal sponsor of the bill, called the lawsuit an "absolute insult to the rule of law," telling the Associated Press that, "It's clear they don't want [immigration] laws enforced."
However some in Phoenix are applauding the lawsuit.
"Fifty years ago, sixty ago, at the height of the civil rights movement when states, Governors, state legislators passed laws and legislation that were discriminatory, bigoted, prejudiced, totally against the constitution. It took the federal government to step in and say we are the United States of America and we will not allow states to overshadow the federal government," said Rev. Walter Stewart, a Pastor at First Institutional Baptist Church in Phoenix.
The Arizona immigration law passed in late April. The controversial law that has attracted international attention and sparked protests around the country essentially gives Arizona law enforcement greater authority to look for and arrest illegal immigrants.
The bill would allow police to question and arrest people without warrant if there is "reasonable suspicion" about their immigration status, and to charge undocumented citizens with "trespassing."
People would have to carry proof of their immigration status and could be arrested if they don't have proper documents. It would become illegal for people to employ illegal immigrants or to transport them anywhere in the state, even if they are family members.
A number of police chiefs, including those from Phoenix and Tucson, came to the Department of Justice today to meet with Holder to discuss their opposition to the new law.
The police chiefs told Holder that the law is driving a wedge between them and people in their communities. Other chiefs that attended included those from Los Angeles, Philadelphia, Houston and the Arizona Chiefs Association.
The Associated Press contributed to this report.