"A door has been opened," said Rep. Geraldine Ferraro in her concession speech Tuesday night, "that can never be closed again." She's right. Her selection by Democratic presidential candidate Walter Mondale to be his running mate was a high-stakes gamble. It may not have paid off in the way that was expected, but Rep. Ferraro's candidacy nevertheless changed the political landscape and was instructive in unexpected ways.

It would have been naive to assume that women as a group -- if a majority of the population can be so categorized -- would cast their lot with a ticket simply because a woman was running on it. This did not happen, and shouldn't have anyway. That is the wrong basis for choice. In fact, most women, like most men, voted for Reagan-Bush this week, and the slightly smaller margin given by female voters is plausibly explained by gender differences on issues -- poverty and peace, for example -- rather than on personalities.

It must also be said that Rep. Ferraro had far less experience in government than most vice presidential candidates and had to work hard to catch up on substantive matters. Nor had she received the kind of scrutiny by the press and the public that most candidates at this level have experienced. At the beginning of the campaign she says she warned her husband that charges would be made about family connections and finances as they had been, to some extent, in her first congressional campaign. But certainly she never realized how rough it would be when the stakes were this high. Perhaps if Rep. Ferraro had entered the presidential primaries, as many vice presidential candidates have done, all the questions would have arisen earlier, been dealt with quickly and settled before the main event began.

Nevertheless, she was a good candidate and ran a campaign to be proud of. There was no whining or self-pity, no blame-shifting or vacillation. She worked hard, kept her sense of humor and faced up to pressure and stiff questioning with intelligence, candor and style. There will always be some who won't vote for a woman under any circumstance, but their numbers are diminishing with time. There will always be some who will vote for any woman simply because of her sex, but their numbers will now be augmented by those who are willing to judge a candidate without regard to sex.

It was not necessary for Geraldine Ferraro to be elected vice president to make history. Her nomination and her campaign ensure that from now on women will be considered for high public office not as tokens or obligatory fixtures on every national ticket but by the same standards that are applied to men. She can be proud of that achievement.