By Tim Gaynor
PHOENIX (Reuters) - Opponents of Arizona's tough crackdown on illegal immigration made a bid on Tuesday to challenge a U.S. Supreme Court ruling that will allow police to enforce the so-called show-me-your-papers provision.
A coalition of civil rights organizations asked a federal judge in Phoenix to stay implementation of the key provision of the Arizona law that requires police to check the immigration status of people they stop, the American Civil Liberties Union said.
The immigration status check provision was upheld by the U.S. Supreme Court in late June, in a mixed ruling that also struck down three other sections of the Arizona law.
Plaintiffs including the ACLU, the Mexican American Legal Defense and Educational Fund and the National Day Laborer Organizing Network asked Judge Susan Bolton for a preliminary injunction until she has had time to consider additional claims that the section was "unconstitutional."
The new challenge is part of an existing lawsuit filed two years ago. The rights groups argued in the new motion that the section upheld by the Supreme Court "unlawfully discriminates against Latinos and individuals of Mexican origin" and violates the Constitution.
The groups also presented what they said was "new evidence" that, if it is allowed to go into effect, that section would violate the principle that federal immigration law preempts state immigration enforcement laws.
Arizona's Republican Governor Jan Brewer signed the immigration law in April 2010, arguing that the administration of President Barack Obama had failed to secure the state's porous southwest border with Mexico.
A spokesman for Brewer dismissed the new legal move as "unsurprising," and said the Supreme Court has "already spoken unanimously on the constitutionality of this provision."
"Governor Brewer is hopeful Arizona law enforcement will soon at long last be empowered to enforce SB 1070, showing that it can be done fairly, lawfully and in harmony with civil rights and the Constitution," the spokesman, Matthew Benson, said in a statement.
"Ultimately, that's the only way that residents of this State will be able to put to rest the fear-mongering and outrageous allegations made by opponents of SB 1070," he added.
The Obama administration challenged Arizona's immigration crackdown in court two years ago, saying the U.S. Constitution gives the federal government sole authority over immigration policy.
Critics say the Arizona law will lead to racial profiling in a state where Hispanics represent nearly a third of its 6.5 million people. Of those, an estimated 360,000 are illegal immigrants. Most U.S. illegal immigrants are Hispanics, with many entering the country through Mexico.
In its June 25 ruling, the Supreme Court struck down three provisions. They required immigrants to carry immigration papers at all times, banned illegal immigrants from soliciting work in public places, and allowed police to arrest immigrants without warrants if officers believed they had committed crimes that could warrant deportation.
In court papers lodged on Tuesday, the plaintiffs also asked the judge to block a separate provision of SB 1070 that creates a state crime for "harboring" undocumented individuals, which it argued was "unconstitutional" in light of the Supreme Court ruling.
(Additional reporting by David Schwartz.; Editing by Jackie Frank and Christopher Wilson)