Phoenix, Arizona (CNN) - With scant hours to go before a controversial Arizona immigration law goes into effect, a federal judge granted a preliminary injunction Wednesday against the implementation of parts of the law.
There are seven lawsuits seeking to block its implementation. U.S. District Judge Susan Bolton made her ruling on a lawsuit filed by the federal government.
The law, signed by Arizona Gov. Jan Brewer in April, requires police to question people about their status if they have been detained for another reason and if there's reason to suspect they're in the United States illegally. It also targets those who hire illegal immigrant laborers or knowingly transport them. It is to go into effect Thursday.
Opponents say the law will lead to racial profiling, which is illegal.
Supporters point out that the law prohibits racial profiling and people cannot be stopped and asked for proof of legal residence based solely on their looks.
In addition to the U.S. Justice Department, the American Civil Liberties Union, the National Coalition of Latino Clergy, the Christian Leaders League of United Latin American Citizens and other individuals or groups have asked the judge to halt the law, commonly known as SB 1070. Bolton heard arguments in the case last week from the Justice Department and the ACLU.
The separate hearings were held in Phoenix, where Bolton sits on the U.S. District Court for the District of Arizona.
Bolton's courtroom was packed during the two July 22 hearings and protesters chanted outside throughout the afternoon.
Seven protesters were arrested on civil disobedience charges, according to the National Day Laborer Organizing Network.
The legal arguments revolved around a range of issues, including racial profiling, effective enforcement and possible harm to Arizona's citizens.
Attorneys from the Obama administration presented their case at the second hearing. The administration's challenge contends Arizona's law would usurp federal supremacy on immigration.
Brewer attended the hearing.
Arizona has argued that the federal government has not done a good job of securing the border.
"A law unenforced is no law at all," said state attorney John Bouma.
The American Civil Liberties Union and a coalition of civil rights groups argued earlier in the day that the controversial law amounts to racial
profiling and will have a profound effect if it goes into effect.
"It treats people of color as suspects first, rather than citizens," attorney Karen Tumlin said after the hearing.
Bouma said the law would not treat people unfairly.
"These are hypothetical arguments. Local police are enforcing immigration laws all over the country," he told Bolton.
Those in favor of the law say SB 1070 is consistent with federal law.
They say the law explicitly prohibits racial profiling and they are challenging the legal standing of many of the groups opposed.
They also contend opponents of the law have not been able to show there will be any harm from its implementation.
During the first hearing, Bolton said the law has a section allowing parts to still take effect even if other parts are struck down, according to CNN affiliate KNXV.
Tumlin, managing attorney for the National Immigration Law Center, and other lawyers and foes of SB 1070 repeated assertions that Arizona's law should be rejected.
"We are here to defend the rights of those who cannot stand up for themselves," said Terri Leon, CEO of the Friendly House, which supports the legal challenge by the American Civil Liberties Union.
Bolton heard a challenge to SB 1070 by an Arizona police officer the previous week.
Read the full ruling here [pdf]