Judgment time is approaching for Joe Arpaio, the man who calls himself “America’s Toughest Sheriff.”

The controversial law enforcement chief of Maricopa County, Ariz., soon will hear a federal judge’s ruling in a class-action lawsuit charging a pattern of racial profiling in the targeting and detention of Latino drivers and passengers during traffic stops. Closing arguments were heard this week.

Meanwhile, the US Justice Department is proceeding with its broader discrimination case against Sheriff Arpaio, the department he oversees, and Maricopa County itself.

“Latinos in Maricopa County are frequently stopped, detained, and arrested on the basis of race, color, or national origin, and Latino prisoners with limited English language skills are denied important constitutional protections,” the Justice Department charges. “As a result of the pattern or practice of unlawful discrimination, Latinos in Maricopa County are systematically denied their constitutional rights; the relationship between MCSO [the Maricopa County Sheriff's Office] and key segments of the community is eroded, making it more difficult for MCSO to fight crime; and the safety of prisoners and officers in the jails is jeopardized.”

While Arpaio vigorously denies the charges in both cases – he refused to cooperate in an earlier Justice Department investigation, calling it "a political witch hunt" – his controversial approach to law enforcement and his outspoken opposition to illegal immigration may be chipping away at the personal popularity as well as the political support he’s enjoyed over his six terms as sheriff.

A recent poll of 600 likely voters in Arpaio’s race for another term showed his favorability rating dropping to just over half (53 percent) with 65 percent opposing what they see as Arpaio's politicizing of the office – specifically, Arpaio’s controversial volunteer “Cold Case Posse” questioning the legitimacy of President Obama’s birth certificate, an issue that seemed to have nothing to do with the debate over immigration enforcement.

Still, 76 percent of respondents to the poll, which was conducted by a group critical of Arpaio, give him high marks for being tough on crime. And Arpaio seems to welcome publicity and controversy – good or bad. He granted interviews and encouraged the 6,000-word profile in the current issue of Rolling Stone magazine, which describes him as “America's meanest and most corrupt politician.”

And in a state that has seen much political turmoil over illegal immigration, including a US Supreme Court decision in June that struck down most provisions of Arizona’s tough law, Arpaio’s position on the issue does not necessarily provoke a fight from those who would challenge him – other than that it’s a distraction from fighting other crimes.

In a new ad this week, Democratic challenger Paul Penzone, a retired Phoenix police officer, charges that Arpaio’s office mishandled 400 sex crimes – including those involving children (a point made in the Justice Department investigation as well). “This will never be tolerated under my watch,” Mr. Penzone says in the ad. In another ad, Penzone says that Arpaio’s joining the “birther” movement questioning Mr. Obama’s citizenship “is an insult to law enforcement.”

But ousting Arpaio is likely to be an uphill battle. He has nearly $7 million in campaign funds – most of it from out-of-state donors. Penzone last reported $140,000 in campaign funds, and he still faces a party primary later this month.

Arpaio has repeatedly denied charges that his department discriminates against Latinos, saying his deputies only stop people when they think a crime has been committed.

The plaintiffs in the class-action lawsuit, who argue that Arpaio’s departmental policies violate the rights of Latinos under the Equal Protection Clause and the Fourth Amendment to the US Constitution, aren't seeking monetary damages, the Associated Press reports. Instead, they want a declaration that Arpaio's office uses racial profiling and an order requiring policy changes. If Arpaio loses the civil case, he won't face jail time or fines.