The Department of Justice this week filed a lawsuit against the state of Arizona, claiming that its immigration law, S.B. 1070, unconstitutionally interferes with the federal government’s authority to set and enforce immigration policy.

S.B. 1070, which made failure to carry immigration documents a crime and allows police the discretionary power to detain anyone suspected of being in the country illegally, has been knocked by critics as the broadest and strictest immigration measure in generations.

The department’s brief said that S.B. 1070 will place significant burdens on federal agencies, diverting their resources away from high-priority targets, such as aliens implicated in terrorism, drug smuggling, and gang activity, and those with criminal records.

“For 75 days, we’ve been praying for this law to be struck down,” said Petra Falcon, executive director of the non-profit organization Promise Arizona, in a statement. She added, “We applaud the Obama Administration for standing up to this misguided law and reestablishing that immigration enforcement is a federal matter.”

In a brief submitted by the Justice Department, Arizona law enforcement officials said that S.B. 1070 has hampered their ability to effectively police their communities. Officials have also said that victims or witnesses to crimes would be less likely to come forth or be cooperative with investigations for fear of a potential arrest.

The main argument made by the department is that Arizona has proceeded to create a state-specific immigration law that intentionally supplants that of the federal government. “Arizonians are understandably frustrated with illegal immigration, and the federal government has a responsibility to comprehensively address those concerns,” said Attorney General Eric Holder in a press release from the Department of Justice.

“But,” he continued, “diverting federal resources away from dangerous aliens such as terrorism suspects and aliens with criminal records will impact the entire country’s safety.” The department has also requested a preliminary injunction – which would prevent Arizona from enforcing the law until the case is heard— to enjoin enforcement of the law, arguing that the law will cause irreparable harm.

“S.B. 1070 does not simply seek to provide legitimate support to the federal government’s immigration policy, but instead creates an unprecedented independent immigration scheme that exceeds constitutional boundaries,” the department said in its brief.

Republican National Committee (RNC) Chairman Michael Steele denounced the move on Tuesday, however, saying Arizona was just doing what was necessary to protect its borders.

“It is unfortunate that President Obama and his administration would rather wage a costly legal battle with Arizona than allow the state to take the concrete steps necessary to secure its border,” Steele said in a statement. “Arizonans are fed up with waiting for the help promised by Washington that never seems to come. The state of Arizona has the right and the responsibility to provide security and stability for its citizens when the federal government fails to do so.” Steele further claimed that the White House was again avoiding taking on immigration reform.

“Not only will a lawsuit not solve the problem,” he said, “it is just another instance of hollow, political gamesmanship from a White House unwilling to take the bold action necessary to solve one of the country’s most pressing issues.”