Sheriff Joe Arpaio of Maricopa County, Arizona, whose trial in a class-action civil-rights lawsuit continues this week in Phoenix, didn’t get to be America’s most notorious anti-immigrant lawman by being shy. The camera and microphone are blood and oxygen to him. Where he goes, he trails TV crews, a gallery of rabid followers, posse volunteers and, every four years, supplicating Republican presidential candidates. The tent-city jail he calls his “concentration camp” is meant to signify brash, unchallenged power. In the blistering landscape of Phoenix, he blots out the sun.

The people he abuses and humiliates, by contrast, are not Fox News regulars. The men and women hustled into custody by his immigration sweeps are generally undocumented and unknown. The neighborhoods he raids can seem like traumatized places, silent and cowed by the dread Sheriff Joe.

This picture is incomplete. Many Latinos surely avoid any contact with the sheriff and his deputies. But Maricopa is also home to a brave corps of people who have tirelessly and stubbornly resisted the sheriff’s campaign of fear. They are a diverse group — Latinos and Anglos, immigrants and the native-born, street protesters and musicians, filmmakers and bloggers, and a very small number of elected officials. They don’t get much national attention. But as the worst of the outrages of the Maricopa County Sheriff’s Office are exposed this month in United States District Court in Phoenix, their work and their warnings are finally being recognized.

Among the most easily recognizable is a stocky Mexican-American with a white mustache and ponytail, Salvador Reza, an Air Force veteran with long experience in organizing Latino entrepreneurs and day laborers. When Sheriff Arpaio teamed up with local business owners to harass day laborers in 2007, Mr. Reza helped organize weekly protests outside M. D. Pruitt’s furniture store, a now-legendary series of confrontations that drew Minutemen vigilantes and white supremacists to one side of the street, and Mr. Reza and his supporters, accompanied by traditional dancers and musicians, to the other. Mr. Reza has been a thorn in Sheriff Arpaio’s side ever since. Sheriff’s deputies arrested him in 2010 while he was a bystander at a protest; though Mr. Reza was hauled before a judge in prison stripes, a prosecutor admitted he had been arrested without cause, and he was released.