TUESDAY'S ELECTIONS IN Virginia and Florida have improved the chances of the Equal Rights Amendment in both states and buoyed the spirits of ERA backers. Probably the most impressive gain occurred in Virginia's 5th House District, a rural area that spreads from West Virginia to North Carolina, in which a pro-ERA Democratic woman, who had never run for office before, outpolled three anti-ERA Republican male incumbents for the House of Delegates, although two of the Republicans were still reelected in the three-member district.

Joan Munford, a former schoolteacher who runs a chain of family-owned nursing homes, was the only Democrat who agreed to run in a district that has not elected a Democrat since 1965. "There was no way I could win," she said. "When we figured it out mathematically, if I had been the top choice of 7 out of 10 people and they had voted for me and two Republicans, I still would have lost the race. I knew the mathematics were against me."

Munford says some Democrats voted only for her, and she picked up support from Republicans and independents. And she says that pro-ERA volunteers "may have had a great deal to do with the fact that I won the election."

Hundreds of pro-ERA volunteers from the Virginia Women's Political Caucus and from the Virginia chapter of the National Organization for Women supported the Democratic ticket and pro-ERA legislative candidates. ERA volunteers identified 45,000 pro-ERA households in Fairfax and targeted them with phone calls and mailings endorsing candidates and urging them to vote. Munford's win should be instructive to other politicians in unratified states such as Virginia, because it is clear not only that her pro-ERA position was popular in a traditionally conservative district but that it got her volunteers that she believes may have won her the election.

Marianne Fowler, chair of the Virginia Women's Political Caucus, says ERA backers picked up three votes as a result of the election. Ten of the 12 seats in Fairfax and all of the seats in Arlington and Alexandria are now held by pro-ERA legislators. Gwen Cody, a right-wing candidate, was the third vote-getter in Fairfax's 49th District, trailing two pro-ERA Republican men but defeating three pro-ERA Democrats. "The pro-ERA vote was splintered," says Fowler. "That's how she got elected." Democrat Dorothy McDiarmid, ERA's chief sponsor in the House and a target of the right wing, was reelected.

"There's a general malaise in the population now," says Fowler. "Women have made so many gains, they had not felt the pressing need for a constitutional protection. Then along came Ronald Reagan . . . I can't tell you how many phone calls I got from all over the state in the last two weeeks saying, 'Tell me who the ERA candidates are so I can support them.' "

ERA also got a boost in two special elections in Florida where pro-ERA candidates defeated anti-ERA candidates for a seat in the state House and another in the Senate. Hundreds of NOW volunteers worked in the Florida campaigns, according to NOW president Eleanor Smeal, and the pro-ERA candidate won with 60 percent of the vote.

Fowler and Smeal both say that ERA has a better shot in Virginia now than ever before. There are six vacancies on the House Privileges and Elections Committee where the amendment has been bottled up in the past. The speaker of the House is opposed to ERA and in the past has appointed members to the committee to reflect his anti-ERA views. The newly elected governor, lieutenant governor and attorney general favor ERA. The question now is how much of an issue do they want to make of it. During the campaign, governor-elect Charles S. Robb said he thinks it would be fruitless for him to get involved in the Virginia legislative fight over ERA.

Newspaper polls before the election showed women preferring Robb by l7 and l8 percentage points more than men. Smeal says it is ERA and the perception that Reagan is against women that influenced women to vote for Robb over Republican Marshall Coleman. Democrats are identified as more pro-ERA, and in Robb's case both his wife and mother-in-law are identified as strongly pro-ERA. Women, says Smeal, "felt the door was being slammed on the other side."

All sorts of analyses are being made of the Virginia election. Several things are clear. The difference in the way that women feel about politics from the way men feel -- a difference that has been consistently showing up in national polls about Reagan -- also exists in the way women feel about state races where issues of war and peace are not a factor. What is a factor, and Joan Munford is a clear example of this since it inspired her to run, are Reagan's economic policies and the perception that they hurt women and children and the elderly poor. And in a state as conservative as Virginia, there is clearly a strong pro-ERA sentiment that galvanized hundreds of volunteers and sent only two anti-ERA people to Richmond from Northern Virginia and sent Joan Munford to Richmond from a rural Republican area.

The man she upset was the Republican minority leader of the House. When the state legislature convenes in January, the members who are against the Equal Rights Amendment and those who don't think it matters to voters in Virginia would do well to remember Jerry Geisler.

He's the man who didn't return.