Early this year, when Missouri Sen. Harriett F. Woods decided to run in the Democratic primary for the U.S. Senate, party leaders encouraged her. Democrats were not exactly knocking down the doors for a chance to run against John Danforth, a popular Republican incumbent and heir to a dog food fortune. Then, the polls on Reaganomics started pointing to trouble for Republicans, and Missouri party leaders took a hard look at the candidate they could be fielding against Danforth. They didn't like what they saw.

Woods is a city woman who has a progressive record in the state Senate. She supported the Equal Rights Amendment. Worse, she had a prochoice position on abortion. The traditional political wisdom of the conservative, rural state of Missouri held that Woods would not be a match for Danforth. Into the primary race came Burleigh Arnold, a banker-lobbyist and a leading Democratic fund-raiser, who brought with him the support of the party leaders.

"Suddenly," says Woods, "they were telling me to get out. You can't expect any support and you'll have to run against the establishment and you don't want to do that because it will ruin your career.

"I think it was the most difficult night of my life, deciding whether we would go it alone. I really felt strongly that if I backed off when I felt I was the most prepared person to run, it would be impossible for any woman to run statewide in Missouri without being handpicked. I'd made all those speeches to women's groups about taking risks. I just couldn't let everyone down."

She did not. In four months, Woods built a state-wide organization and raised $250,000 from more than 4,000 contributors. On Aug. 3, she scored a stunning 2-to-1 victory over Arnold, getting 254,000 votes to his 122,000. "I took 80 out of 114 counties in Missouri," Woods recalls. "In a good many of the others, I barely lost. That really set them all on their heels." The same night, Danforth won his primary with 204,000 votes, 72 percent of the Republican primary votes cast in the heavily Democratic state.

If this turns out to be the year of the women's vote, Woods is turning out to be -- in the word of The St.Louis Post-Dispatch -- a "formidable" woman candidate. She has demolished the traditional notion of southern party leaders that a woman can't win in rural areas and that a prochoice woman can't win in Missouri. She won the support of unions, another shock to party leaders. And she has demonstrated that voters are way ahead of party leaders in backing women candidates. "What once seemed an untouchable race is a wide open election," says Ann Lewis, political director of the national Democratic Party.

Lewis believes that being a woman will work to Woods' advantage. "All other things being equal, there is an increasing edge to women candidates," Lewis says. "In a year in which people have reason to feel the institutions just aren't working in their interest, there is a real appeal in a candidate like Harriett Woods who comes from outside the institutional leadership.

"People believe of a woman candidate that she understands what their lives are like. Women, no matter whether we hold office or not, are responsible for half of the household duties. We know what the price of groceries are this week. When the household economy is the biggest thing on people's minds, they feel that a woman candidate is more likely to understand that from first-hand experience."

Ronald Willnow, assistant managing editor of The St. Louis Post-Dispatch and a former political writer for the paper, says the margin of Woods' victory was an "overwhelming surprise . . . . She's proved to be a much better vote getter than anyone anticipated."

Woods will be running against a tough incumbent: a Republican with a moderate image who expects to raise $2 million for the general election. At best, Woods hopes to raise $1 million.

"I am going to continue to emphasize that I am closer to people," Woods says. "My husband and I have raised three children on a very average income. We understand what it means to pay bills, send our children to public schools and worry about retirement income. At the same time, I have a public record people can look at."

Unlikely as it may seem, the Democratic voters of a conservative, traditional state such as Missouri chose one of a new breed of political leader: a progressive woman who makes a point of being one of them, someone who defied the party leaders and did it on her own. She offered voters a change of politics. As the November forecasting game gets under way, it is worth remembering how convincingly she won.