At 30, she's chopped cotton, babysat for $1 a day, been to jail for picketing, and endured tear-gassing at college. Now, Annie Moore is chairwoman of the Young Democrats of Mississippi. Yesterday she left here for her Gulf Coast home, one of the legions with the task -- a difficult one, at best -- of selling Jimmy Carter's promises to black Americans.

As the first black woman to chair the predominantly white Young Democrats in a state where the party includes not only the traditional conservatives and liberals, but segregations, separatists and state-righters, Moore is a telling gage of how the position of blacks has changed in the state. After all, Mississippi is a state that said "Never," a state once considered so dangerous for outspoken blacks that mothers used to ship their sons to stay with Northern relatives.

At about the time Annie Moore was demonstrating to get the swimming pool in her Edwards, Miss., birthplace desegregated, another Mississippian, Aaron Henry, was prying open the old-white-boy network that characterized Democratic Party politics by initiating the fight to get the racially mixed Mississippi Freedom Democratic Party seated at the 1964 Democratic convention. That fight eventually to major reforms within the national party.

This week, Democratic National Convention delegate Aaron Henry would say of the young woman who names him as one of her heroes: "Everybody knows Annie is chairperson of the Young Dems. Nobody messes around with her."

Moore feels more confident about the blacks in her Bible-belt state supporting born-again Christian Carter than many other blacks, who left here asking themselves "Jimmy How?"

Selling Carter is easy when the alternative is Ronald Reagan, she says, and she intends to shift the focus. "More than Carter not delivering, I intend to stress that Congress did not deliver," she says.

But if Annie Moore is charged with getting out the black vote, she is symbolic, too, of new black political clout in a nonracial arena. It is an arena of age bias, and she must get her group into a power position with the state's senior Democrats, some of whom see the Young Dems as sturdy legs but not serious voices.

But Moore is used to negotiating. As one of nine children, she learned the art of compromise early on. "With nine siblings you know you don't always get your way. You try to have your way when you can, but you understand your options."

Orphaned by the time she was 10, (an older sister raised the seven younger children), Moore nonetheless gained a strong personal identity from her domestic-worker mother and sharecropper father. A serious look flashes across an attractive face as she remembers: "When you grow up without parents, you have to rely on yourself. We had to learn to be happy about things at a very sad time."

Politics entered her blood when she started demonstrating in the 1960s, joining the marches, opening her home to the voter registration workers. Her awareness sharpened, she saw with a jolt her second-class citizenship; she wanted to be involved. While earning two degrees at Jackson State College, she married her high school sweetheart, had a daughter, got a divorce, and still yearns today for a man who won't think she's anti-family because she is pro-career. But it would be the mid-1970s before she would take the steps that led to where she is now.

About the time she relocated in Gaugier, Miss., to take an administrative job at Mississippi Gulf Coast Junior College, she went to Washington to a Presidential Classroom for Young Americans and came away "amazed" at the intricacies of the federal government.

Recognizing her ignorance about how her own state worked, the next year she attended a six-month Institute of Politics in Jackson, commuting nearly 400 miles round-trip every other Saturday for six months. She met elected officials from around the state -- men like Charles Evers and Aaron Henry -- who not only talked but accomplished things. Then she put all she had experienced together and began working at the precinct level and in caucuses. She says she doesn't have personal political aspirations but rather "a great deal of belief in black people and people in Mississippi."

Expertly weaving her way through the convention action and excitment, Annie Moore gives the impression of an assertive, happy-go-lucky woman, supremely confident in her ability to go wherever she wants to go, but acutely aware that as a black woman in a white man's world, she has to work harder to prove herself. But there is a quintessential sadness beneath the surface, a seeking that has little to do with her ascending political star.

"If I had one dream, it is one of being a happily married black woman with a family. Everything else I have done or can do," she says. She knows that a man who can accept her with her ambitions is exceptional, but still she seeks a marriage "to share my personal self with someone."

Being a first is not easy; being a symbol is tough, but exercising real clout is even tougher. Annie Moore is part of the new reality of America, a woman who prefers to fight for change in the heart of the Deep South.

"I have been determined to stay in Mississippi," she has concluded. "Everything I am about can exist for me there."