Mr. Obledo, one of 13 children raised by a single mother in San Antonio, has been called the godfather of the Latino civil rights movement for his efforts to raise Latinos' profile as a political force.

A lawyer by trade, he co-founded the Mexican American Legal Defense and Educational Fund in the late 1960s and served as its first general counsel, using the courts to fight discrimination against Latinos in the workplace, in public schools and elsewhere.

He also co-founded the Hispanic National Bar Association and the National Coalition of Hispanic Organizations, and he played an early leadership role with the Southwest Voter Registration Education Project, which works to boost the number of Latino voters.

In 1975, he was tapped by California Gov. Edmund G. "Jerry" Brown Jr. to head the sprawling Health and Welfare Agency, overseeing more than 50,000 employees and an annual budget exceeding $11 billion. During his tenure, Mr. Obledo fought allegations that he was tied to the Mexican Mafia and stirred controversy with his unapologetic efforts to hire more minorities into state government.

He served until 1982, when he resigned to run unsuccessfully for governor.

In the mid-1980s, he served as president of the League of United Latin American Citizens, the nation's largest and oldest Hispanic American organization. He was outspoken on issues including immigration reform and bilingual education, and he refused to accept what he considered the scant attention mainstream political candidates gave Latinos.

At the 1984 Democratic National Convention, he urged Latino delegates to boycott voting on the first ballot to reprimand the presumed presidential nominee, former vice president Walter F. Mondale, for ignoring issues important to them. Asked whether sending that message to Mondale was more important than defeating President Ronald Reagan, Mr. Obledo replied: "I'm a Democrat and I love my party. But I love my community more."

Mr. Obledo served as chairman from 1988 to 1993 of the National Rainbow Coalition, the left-leaning organization founded by Jesse Jackson after his 1984 presidential bid. Then Mr. Obledo largely faded from view until 1998, when Bill Clinton awarded him the Presidential Medal of Freedom, the nation's highest civilian honor.

Clinton said Mr. Obledo "created a powerful chorus for justice and equality," citing as an example his efforts in 1970 on behalf of Latino children who were banned from a public swimming pool in Texas.

Mr. Obledo drove 200 miles to the pool and was told he couldn't enter. He brought suit, and when he won, Clinton said, "even the joy in the courthouse could not match that of Mexican American children whose civil rights had been defended, as finally they had a chance to jump into that public pool."

Also in 1998, Mr. Obledo made a series of statements that landed him at the center of the national debate over race and immigration.

"It's inevitable that Hispanics or Mexican Americans are going to control the institutions of the state of California in the not-too-distant future," he told the Los Angeles Times. "If people don't like that, they can leave."

He called for a boycott of the fast-food chain Taco Bell, because of its commercials featuring a Chihuahua speaking with an accent, and vowed to destroy a billboard that had been erected in Blythe, Calif., near the border with Arizona.

"Welcome to California, the Illegal Immigration State," the sign said. "Don't Let This Happen to Your State."

Mr. Obledo called the sign racist and promised to burn it down, a threat that gave rise to demonstrations and counter-demonstrations. Even as the issue raged in the media, many Latino activists distanced themselves from Mr. Obledo and his tactics.

He said he understood that resistance. "We're generally a law-abiding community," he said of his fellow Latinos. "But I felt that was an action that needed to be taken."

The billboard was eventually removed.

Mario Guerra Obledo was born in San Antonio on April 9, 1932. His father died when he was 5, and he and his siblings grew up on welfare with their mother.

He served in the Navy during the Korean War and then graduated in 1957 with a pharmacy degree from the University of Texas at Austin. He worked as a pharmacist to put himself through law school at St. Mary's University in San Antonio, from which he graduated in 1960.

Mr. Obledo worked for the Texas attorney general's office before he was chosen in the late 1960s to help establish the Mexican American Legal Defense and Educational Fund by a San Antonio lawyer who had secured financial support from the Ford Foundation.

One of the first issues Mr. Obledo took on was employment discrimination by local public utilities, which were known for prohibiting the hiring of anyone who had an accent or was shorter than 5-foot-10. Mr. Obledo argued that such policies unfairly targeted Latinos.

"I remember arguing the case with a manager from Southwestern Bell," Mr. Obledo recalled in a 2001 interview with the San Antonio Express-News. "I asked him, 'You mean to tell me that you wouldn't hire Mrs. Lyndon B. Johnson because she has an accent?' "

Mr. Obledo taught briefly at Harvard University's law school before Brown appointed him secretary of health and welfare.

His first marriage, to the former Mary Robles, ended in divorce.

Survivors include his wife of 15 years, Keda Alcala-Obledo of Sacramento; three children from his first marriage, Mario Obledo Jr. and Sybil Obledo of San Antonio and Sylvie Obledo of Santa Fe, N.M.; nine sisters and brothers; and four granddaughters.