Will the 'gender gap' be a factor this fall?

This election is a major test for the women's vote. Only two years ago pollsters discovered a potentially powerful force in US politics, the so-called "gender gap."

For 60 years since winning the vote, women followed men in lockstep. But in the 1980 elections, millions of women broke rank, voting against Ronald Reagan in greater numbers than did men.

The 1982 congressional elections will offer proof of the staying power of the new woman's voting bloc.

"When women got the vote, they simply paralled the male vote," says Judy Goldsmith, president-elect of the National Organization for Women (NOW). "I don't think we effectively made use of it until now."

Political analysts see the new bloc as leaning heavily Democratic. A recent poll in a tight US Senate race in Virginia, for example, found a 25 percent difference between men and women. Women favor Democrat Richard J. Davis over Republican Paul S. Trible Jr.

According to Goldsmith, the GOP is losing women because of cutbacks in domestic programs and civil rights enforcement. Others see the gender gap as related to "women's issues" such as peace, education, and treatment of the elderly.

If the women's bloc makes the difference in close elections this fall, it will give women greater clout in future campaigns. Already campaign professionals are advising candidates to hire more women in visible campaign jobs, and office seekers are featuring women prominently in their TV spots.

This year will also be a test for groups trying to elect men and women sympathetic to women's rights. Among the important races:

* State Sen. Harriett Woods has run a surprisingly strong race against incumbent US Sen. John C. Danforth of Missouri. Woods mounted a successful grass-roots campaign in the primary. If she wins, it would be a major boost for women's rights groups.

* Equal Rights Amendment supporters would like to elect former Sen. Adlai E. Stevenson III (D), to replace Illinois Gov. James R. Thompson (R). Mr. Thompson is widely blamed for defeating the ERA in his state.

* Former US attorney Roxanne Conlin, an Iowa Democrat, is running for the governor's seat against Lt. Gov. Terry Branstad, a Republican. Conlin, favored by NOW, seemed to be close to victory until it was disclosed that she and her husband had sheltered most of their income from taxes. However, she is still given some chance of winning.