A U.S. federal judge has cleared the way for the border state of Arizona to begin enforcing a controversial part of a state law that requires police to check the immigration status of people stopped during the investigation of other crimes.
The ruling requires authorities to question those suspected of being in the country illegally.
The requirement is the centerpiece of a contentious piece of immigration legislation at the center of a two-year legal battle that ended in June with the U.S. Supreme Court upholding the key provision. Several other parts of the law were rejected.
A coalition of civil rights lawyers and immigration advocates asked a federal district court judge in July to block the immigration status requirement, arguing that it would lead to systematic racial profiling and long detentions of Latinos if enforced. The court rejected that request Wednesday.
Ahead of the latest ruling, lawyers for Arizona Governor Jan Brewer urged the court to let the requirement -- dubbed the "show-me-your-papers" clause -- go into effect. They argued that opponents were merely speculating about the potential for racial profiling -- a practice of targeting individuals for searches based on race that the High Court found unconstitutional in 1996.
Opponents of the Arizona law argued that people detained under the papers clause would be kept in custody longer than constitutionally permitted while their status was checked.
Immigration has been a hotly-debated topic this year in the primary campaigns for the U.S. presidency. Both President Barack Obama and Republican challenger Mitt Romney are courting Hispanic voters -- many of whom have voiced strident opposition to the measure.