Days after Elizabeth Warren ended her Democratic presidential bid — the sixth and final woman to exit the race — the eventual primary winner, former vice-president Joe Biden, pledged to select a woman as his running mate. On Tuesday, Biden made good on his promise by choosing Kamala Harris.

Historically speaking, women have not fared well as vice-presidential picks or presidential hopefuls. This month, many celebrate the 100th anniversary of the ratification of the 19th Amendment, which secured women’s suffrage at the federal level, although in many places women of colour did not gain the vote until after the 1965 Voting Rights Act.

But after a century of formal inclusion in American politics, Harris is only the fourth woman to appear on a major-party presidential ticket, and the first woman of colour to do so. None of the previous three — Geraldine Ferraro, Sarah Palin or Hillary Clinton — was victorious.

If it happened, Harris’s vice-presidency would be an important symbolic victory as we mark the suffrage centennial after several years of events that have exposed the nation’s persistent racism and misogyny.

But to truly be transformative, Harris will need to be a real governing partner for Biden — as he was for President Barack Obama. That is the only way to ensure that women’s voting power translates into real political influence at the highest level.

Women’s national political clout has been growing for decades.

As feminist groups focused on securing equal rights for women, they also sought more political power. The non-partisan National Women’s Political Caucus was formed in 1971 to elect more female candidates to office. Women soon made sizeable gains in state legislatures, where their representation increased by 50 per cent between 1972 and 1974.

In Congress, a record-setting five women of diverse backgrounds were elected in 1972. Women had traditionally assumed seats once held by a deceased husband or male family member. But these women were lawyers who ran in their own right. Some such as Pat Schroeder brought husbands and young children to the Hill, forcing a redefinition of who could be a legislator.

Four years after Shirley Chisholm became the first black woman elected to Congress, Yvonne Burke made history in 1972 as the first African-American woman elected to Congress from the West Coast — and again, in 1974, as the first member of Congress to give birth to a child while in office. These were important inroads, but not enough. Women gained only one or two congressional seats every cycle until the 1990s.

A landmark came in 1992, which was dubbed the year of the woman. The year before, the all-male Senate Judiciary Committee, chaired by Biden, questioned the veracity of Anita Hill’s sexual harassment claims against Supreme Court pick Clarence Thomas, infuriating many women. Frustrated voters flocked to the polls, and the number of women in Congress increased from 32 to 54 — a record-breaking jump of four percentage points. It remains the largest percentage increase of seats held by women in a single election cycle.

Women’s representation continued to grow over the next decade. In 2002, Nancy Pelosi broke a glass ceiling as the first woman to lead either party in either house of Congress. Five years later, she became the first female Speaker of the House. Now women were not just in the room, but seated at the decision-making table.

The election of Donald Trump spurred an outpouring of activism and organising by women, which paid off in the 2018 midterms, when voters sent the largest and most diverse group of women to Congress. The total increased from 110 to 127 women (or about 24 per cent of Congress), including 48 women of colour (or about 38 per cent of women serving). The Senate, a chamber that did not have more than two women serving simultaneously until 1992, is now one-quarter women.

Despite these strides made in Congress, the track record for female presidential and vice-presidential candidates has been poor.

Women increasingly ran for president in the 1960s and 1970s — notably Chisholm and Patsy Takemoto Mink, a third-generation Japanese-American legislator from Hawaii, who both made a play for the 1972 Democratic presidential nomination. Yet, no women came close to their respective party’s nominations.

After Jimmy Carter’s re-election bid suffered from stormy relations with feminists in 1980, Carter’s vice-president, Walter Mondale, knew not to repeat this mistake as the 1984 Democratic presidential nominee. Feminists had become a crucial bloc within the Democratic Party as antifeminist “family values” activists took over the GOP, and Mondale needed their support.

More than a year before the 1984 election, former representative Bella Abzug and her feminist allies began pressing the Democratic primary contenders to back their policy proposals and name a woman running mate. They then inflicted what one campaign adviser described as “super-pressure” on Mondale. Eleanor Smeal, former head of the National Organisation for Women, mused openly about challenging his choice on the convention floor if Mondale did not select a woman as his vice-presidential nominee.

This intensive lobbying led the equivocating Mondale to choose Ferraro of New York — the first woman to appear on a major party’s presidential ticket.

This historic selection was a well-calibrated choice for the moment. Ferraro represented the 9th District in Queens — the district where Archie Bunker from the hit TV show All in the Family resided. The district was heavily Catholic, economically depressed, historically Democratic and culturally conservative. These contours meant that while Ferraro was an avowed feminist who excited the party’s base, she was also accustomed to appealing to the type of white married women who had voted for Ronald Reagan in 1980, and found his fealty to “family values” attractive.

Ferraro promised not to end traditional family life. In fact, she said, she lived it, with a husband, three children and a dog — she even drove a station wagon. She supported traditional lifestyles such as hers as well as other arrangements, and promised to use the Government as a tool for protecting various possibilities for the family.

These appeals ultimately fell flat as a stronger economy, Mondale’s clumsy pledge to raise taxes and questions about the tax filings of Ferraro’s husband propelled Reagan to a landslide win.

But the election results highlighted the voting gender gap that also had been observed in 1980. In 1984, men preferred Reagan by seven percentage points more than women.

Ferraro had faced an almost impossible task. On one hand, she had to appeal to her party’s strong feminist constituency, including single women and women of colour. On the other hand, she had to appeal to women — mostly white and married — and other family values conservatives who viewed politics through the lens of the traditional nuclear family, and had been led falsely to believe that a feminist like Ferraro was against the family.

Ferraro backers criticised the Mondale campaign for not doing enough to highlight Reagan’s pitiful record on women, even as one Democratic strategist charged that feminists “can’t deliver their sisters”. Despite the continued influence of feminists within the Democratic Party, the failed Ferraro VP candidacy kept women off the ticket until Hillary Clinton ran.

This idea that feminists were against the family also hurt Clinton in both her 2008 and 2016 presidential campaigns. In 2016, she lost white women by nine percentage points although she won college-educated white women by six points and overwhelmingly won the support of African-American women, after years of being derided as “anti-family” on the national stage.

By contrast, Alaska governor Sarah Palin, John McCain’s 2008 running mate, benefited from the image of the party as pro-family values. But Palin, too, was hamstrung by her gender and maternal role. Pundits openly discussed her ability to run for vice-president while caring for a child with special needs. By the end, Palin’s attractiveness, wardrobe and gaffes, more than her record as governor, became election fodder. Her nomination underscored that gender parity in politics is not a partisan issue.

Since women gained the vote, political leaders have depended on women to canvas neighbourhoods, run phone lines and work the polls. The shift from depending on women to power campaigns to seeing women in power has taken longer. This time, the vice-presidential pick has the potential to be not simply tokenistic, but transformative.

Women’s presence — at all levels — in Biden’s campaign could translate into a lasting redefinition of political leadership after the confetti falls on election night. If she is given the chance to lead alongside Biden, Harris can model a style of governance that delivers the last crack to an enduring political glass ceiling.

• Stacie Taranto is an associate professor of history at Ramapo College of New Jersey and author of, Kitchen Table Politics: Conservative Women and Family Values in New York (University of Pennsylvania Press, 2017). She is co-editor of the forthcoming Suffrage at 100: Women in American Politics Since 1920 (Johns Hopkins Press, August 2020). Leandra Zarnow is assistant professor of US history at University of Houston, author of Battling Bella: The Protest Politics of Bella Abzug, and co-editor of the forthcoming Suffrage at 100: Women in Politics since 1920