The outrages to be presented to the court can be added to a long list of abuses going back years, on the streets of Maricopa and in the sheriff’s jails. As early as 2008, The East Valley Tribune of Mesa, a city outside Phoenix, published a series of articles examining the immigration raids as a law-enforcement disaster. While deputies scoured the county making baseless immigration arrests, they neglected other duties, racking up millions of dollars in overtime and showing up ever later to emergencies while the number of criminal arrests and prosecutions plummeted.

Despite those results, Sheriff Arpaio kept going. Homeland Security Secretary Janet Napolitano could have condemned his actions years ago and refused to work with him. But instead, he was allowed to continue the abuse, even as his squad of immigration enforcers deputized under the federal 287(g) program grew to 160, by far the country’s largest. The sheriff became a right-wing celebrity, courted by politicians eager to win the anti-immigrant vote. One of these was Mitt Romney, who accepted his endorsement for president in 2008.

This case is only the first of what is likely to be a string of civil rights challenges against immigration actions in Arizona. A civil lawsuit, brought by the Justice Department, accusing Sheriff Arpaio of systematic and widespread civil rights abuses, is moving through the courts.

Last month, the United States Supreme Court declined to overturn the section of Arizona’s immigration law that requires local officers to check the papers of suspected illegal immigrants. But it said the provision could be challenged on equal-protection grounds, if there is evidence of racial profiling in the way it is carried out. The trial this week does not deal with police conduct under that law, but it does suggest that racial profiling is a deep-seated problem, certainly in Maricopa County.

Sheriff Arpaio is facing the voters for a sixth term this fall. He has long insisted that he answers to no one but the county’s residents, who keep re-electing him. If voters won’t put an end to his abuses, the courts and the Constitution will have the final word.