When Sonia Landau was 33, she divorced her first husband and shed the life of the "young wife" in California, the life of teaching high school and organizing charities, of cooking dinner and sometimes volunteering to pass out leaflets for Republican candidates. That was 15 years ago, and she headed to Washington with no job and few friends. Her ex-husband drove her.

Today, she is known as a top-level Reagan-Bush campaign official who, while wearing her other hat, defeated Democrat Sharon Percy Rockefeller for the chairmanship of the Corporation for Public Broadcasting, a 20-year-old ideological battleground for liberals and conservatives at odds over public television and radio programming. It's a job that already promises to give her more grief than applause.

"Let me tell you," she said recently, "this job does not pay more than $10,000 a year [CPB allows its board members $10,000 each in expenses. There is no salary]. You do it because you're dedicated."

Her election has stirred up those old fears among liberals, including some independent filmmakers, that the half-Republican board is now politicized to the point where it will make an effort to influence programming and funding, as was attempted under the Nixon administration. Historically, Republicans have been known to be more reserved in their enthusiasm for public broadcasting, so critics question whether Landau's loyalty to the Reagan administration will by its very nature directly conflict with her efforts to promote CPB.

President Reagan's September veto of the $685 million 1987-89 authorization funding for CPB hasn't helped matters.

Not long ago, Landau, 47, sat down for lunch armed with her verbal defense, and determined to assert her commitment to public broadcasting. She dressed in a brown coat dress, her hair in a platinum bouffant. As the interview wore on, she became more and more annoyed that her autonomy from the Reagan administration would be challenged by critics.

"Don't we all wish that CPB was that important," she said, "that everybody in the White House was sitting there and saying what are we going to do, what is our next move here? I have been on this board for three years, and I have never once gotten a call or ever been approached by anyone at the White House about CPB programming or funding. Do people honestly think the president sits around with Jim Baker, Ed Meese and Mike Deaver plotting these things?"

"I give Sonia more credit than that," said Geoffrey Cowan, a former Democratic board member. "She is a very hard worker, and I believe she supports public broadcasting. She has publicly disagreed with the administration on occasion -- she is not afraid to do so."

Landau is also faced with concerns by filmmakers that she is in a conflict of interest with her second husband, John Corry, who reviews nonfiction television programs for The New York Times, many of which are shown on public broadcasting stations and have been funded through CPB. The concern is that she could influence programming through her husband's reviews.

"If I praised their works, would that be a conflict?" asks Corry. "There is no conflict. We do not discuss these things. She is not involved in programming. The only instance I can even think of where I wrote about something that she was involved in was advertising on public television. She's opposed to it, and I wrote in favor of it."

Said Lawrence Sapadin, executive director of the Association of Independent and Video Film Makers: "I think it would probably be useful for John Corry to disclose to his readers that his wife chairs a group which funds some of the works that he reviews."

The implication of a conflict infuriated Landau.

"I tell you what I think and that is that this is coming from people who do not want me chairing this board and who would like me off," she said. "There is not one person who has ever worked for my husband who -- you either like him or you don't like him -- has ever doubted his integrity.

"This makes me very angry. This is very unfair. I don't think any of that has to do with any of this. If I were married to a plumber and he was doing work in the CPB building then you would hear comments about whether it's really fair that he has this plumbing contract when I'm in the building. It has to do with the fact that there is a chairman of CPB that happens to be a Reagan appointee and people are worried about it."

Landau wasn't always a Reagan Republican. The only child of a Denver businessman and his wife, she graduated from the University of Denver and later moved to California to study for her master's in politics at Berkeley. Like many of her era, she says she first became a Democrat because of John Kennedy, and worked for him at the 1960 Democratic convention in Los Angeles. "Like most anyone who had seen Kennedy, I was impressed by his manner," she said.

A local Democratic political scandal, she says, turned her head. Her first job in Washington was handling press for the National Republican Congressional Campaign Committee. By 1976, she had relocated to New York and was preparing to take on now-mayor Ed Koch in a race for the "Silk Stocking" district's congressional seat.

"Now I don't want you to think I'm politically naive," she said. "Sometimes women have to run and lose in order to run again."

She got 17 percent of the vote.

After various jobs in advertising firms, and as a media consultant, Landau landed at Reagan-Bush with the help of Reagan's media adviser, Stu Spencer, whom she had known since her days in California. She was first appointed to the CPB board in 1981, after she served on the 1981 transition team. This year Landau directed Women for Reagan-Bush for the campaign.

She said she lobbied for the CPB chairmanship simply because she thought it was time for change.

From the start, CPB has been a hotbed of political wrangling over funding and control. It is managed by a board appointed by the president, and by law not more than six out of its 10 members can belong to any one political party.

Set up during the Johnson administration to act as a buffer between Congress and the White House on the subject of public broadcast funding, CPB filters all federal funds for public television and radio. The Public Broadcasting Service (PBS) and National Public Radio (NPR) receive about one-third of their funds from CPB through the stations. Various television production centers and independent filmmakers are also funded through CPB grants.

Landau is correct when she maintains that the independent filmmakers are always "worried that they are in trouble" and are not happy unless they get "100 percent of what they want," but it's fair to say they had a scare under the Nixon administration when the White House believed the public affairs shows to be in the hands of the liberals.

"The Nixon White House believed there was a liberal bias on public television and tried to directly influence it -- I remember those days," said John Reilly, a self-described "liberal" documentary producer. "I think there is that same danger now -- no proof yet -- but it looks bad."

"When Reagan appointees hit the board, for the first time we heard things like 'the administration's view is not being totally represented,' " said Jose Rivera, a former board member appointed by Jimmy Carter. "We never heard talk like that before. Our concern was whether public broadcasting was being funded, and all of sudden it was whether the White House was being heard."

Although Rockefeller was reappointed to the board by Reagan, Democratic critics are also concerned that the Reagan administration has been reserved in its support of public broadcasting. In 1981, the adminstration attempted to slash CPB funding in half, but was thwarted by a bipartisan coalition in Congress. In August, Reagan vetoed a long-term $761 million funding bill, and then vetoed a $675 million compromise measure two months later.

"Her statement on behalf of CPB after the veto was at best lukewarm," said a Democratic Capitol Hill aide involved in CPB funding authorization who is concerned about Landau as chairman.

Said Landau: "It's a point of style. I don't see any point in crucifying, knocking and attributing all kinds of other motives to people you have to go back and talk to about money."

Although, the critics maintain, there has been no evidence of her gaining administration help, as made vivid by the president's recent veto, Landau said her relationship with the White House can only assist CPB.

"I honestly think the more people you know the better you can present your view," she said. "I mean one person had to win the chairmanship and one had to lose . . . And the fact that a Reagan person won, I think it's a little tacky to keep saying it's political.

"It's good for the institution when you pass leadership around," she said. "Sometimes people just want a change and there's nothing any more complicated than that. They want somebody new there . . . When you're on a board and you're an activist like I am, you want a position of leadership. I am committed to public broadcasting, and I think I can make a difference."