When Joe Arpaio, the tough-talking Arizona law enforcement official, found himself in the awkward position of having his own words used against him in a discrimination lawsuit, the usually brash sheriff was unusually quiet.

The Maricopa County sheriff, testifying in the lawsuit accusing his office of racially profiling Hispanics, spoke in a hush. He said he was suffering from the flu.

Quietly, and clearing his throat often, Arpaio sought to clarify his own public statements that are being used in a lawsuit to prove prejudiced thinking and claims of systematic racial profiling. If lawyers for a group of Latinos win, Arpaio's office would have to make policy changes, though he won't face any jail time or fines.

If the sheriff wins, then the U.S. government would have a harder time proving similar claims in a separate Justice Department lawsuit against him.

The case represents the first time the sheriff's office has been accused of systematic racial profiling. It will serve as a precursor to the federal government's civil rights lawsuit, which is much broader.

Arpaio has long denied racial profiling allegations. He said Tuesday: "We don't arrest people because of the color of their skin."

The plaintiffs, a group of Latinos, say they were discriminated against during sweeps to flush out criminals and illegal immigrants in Maricopa County, which includes the metropolitan Phoenix area. During such sweeps, sheriff's deputies flood an area of a city — in some cases, heavily Latino areas — over several days to seek out traffic violators and arrest other offenders.

The group accused Arpaio of launching some sweeps based on emails and letters from residents who complained that "dark-skinned people" were congregating in a given area or speaking Spanish. The group says deputies in the sweeps pulled over Hispanics without probable cause, making the stops only to inquire about the immigration status of the people in the vehicles.

The sheriff has said that people are stopped only if authorities have probable cause to believe they have committed crimes and that deputies later find many are illegal immigrants.

Arpaio's office maintained that illegal immigrants accounted for 57 percent of the 1,500 people arrested in the 20 sweeps conducted since January 2008, according to figures provided by the sheriff's department, which hasn't conducted any such patrols since October.

Arpaio was asked whether a white person was ever arrested on an immigration violation during the first two years of such sweeps. He replied: "I can't recall."

Lawyers for the group also asked him: Why did you call illegal immigrants "dirty?"

The sheriff said the statement was taken out of context. He added that if a person were to cross the U.S.-Mexico border on foot over four days in the desert, that person "could be dirty."

"That's the context on how I used that word," he said.

Lawyers brought up another statement, one that Arpaio made on a national TV news show. The sheriff had called a 2007 comparison between his department and the Ku Klux Klan "an honor."

Arpaio responded that he doesn't consider the comparison an honor, adding that he has no use for the KKK.

Attorneys also turned to Arpaio's practice of putting county jail inmates in pink underwear, recalling his statements to an anti-illegal immigration group in Houston in 2009.

He said his official reason — "so I can win the lawsuits" — was that the color made the underwear less likely to be smuggled out of jail and sold on the black market.

"And then I have my reasons," he went on. "And my reason is they hate pink. They do. They may like it in California, but they don't like it in Arizona."

He was asked whether he says one thing in court and does another when he leaves.

"This is in humor," Arpaio said. "I make sure we do things properly in case I get sued."

Letters in the sheriff's immigration file also took center stage during his more than five hours of testimony. Plaintiffs' lawyers say Arpaio endorsed calls for racial profiling by passing along ambiguous and racially charged complaints to aides who planned the sweeps and carried out at least three patrols after receiving the letters.

They point out that Arpaio wrote thank-you notes to some who sent complaints.

Arpaio's attorneys denied that the letters and emails prompted patrols with a discriminatory motive.

His lawyers called the complaints racially insensitive and said aides — not Arpaio himself — decided where to conduct the patrols. They also said there was nothing wrong with the thank-you notes.

"He sends thank-you letters because he is an elected official," Tim Casey, the lawyer leading Arpaio's defense, said during opening arguments.

One of the letters he marked for a thank-you was from August 2008, when a woman suggested that the sheriff investigate a Sun City restaurant. It read: "From the staff at the register to the staff back in the kitchen area, all I heard was Spanish — except when they haltingly spoke to a customer."

Arpaio noted in the margins, "letter thank you for info will look into it" and that the complaint should be sent to aide Brian Sands, who selects locations for sweeps, with a notation saying "for our operation." The sheriff's office launched a sweep two weeks later in Sun City.

Arpaio said Tuesday about the particular letter that speaking Spanish is not a crime and that he sent the note to Sands for "whatever he wants to do with it."

Arpaio also said he generally passed along requests for immigration enforcement in a particular area to his subordinates, but didn't do the planning for the sweeps.

"I just send this info to my subordinates so they could ask for it. I don't agree with every letter I receive," Arpaio said.

"We should never racially profile," he said. "It's immoral, illegal."