SANTIAGO, Chile — No one relished the milestone more than President Michelle Bachelet of Chile.
For a few years, she and two other female leaders presided over much of South America, representing more than half of the continent’s population.
Their presidencies — in Argentina, Brazil and Chile — made the region an exemplar of the global push for a more equitable footing for women in politics. And their moment came long before the United States, often regarded as less sexist than Latin America, even came close to electing a female president.
But now, with one of her counterparts impeached and the other fighting corruption charges, Ms. Bachelet finds herself in an unsettling position: the last female head of government standing in the Americas.
And in a few months, she will be gone, too.
After Ms. Bachelet’s term ends next year, none of the countries in North or South America are expected to have female presidents, a notable turnaround in a part of the world where, until recently, women have been elected to lead influential democracies.
“Perhaps we had a cycle of hyper-abundance,” she said during a recent interview at the presidential palace in Santiago.
The end of the Bachelet era is raising troubling questions for advocates of women’s rights who had hoped that the region’s recent track record of electing women was a lasting step toward gender equality.
Dozens of countries around the world, including Chile, have adopted quota systems in an effort to increase the representation of women in government. Yet progress has been stubbornly slow. A goal set by the United Nations in the 1990s to have at least 30 percent of lawmakers in national legislatures be women remains elusive; today, just over 23 percent of legislators are women.
“It’s three steps forward and six steps back,” said Lakshmi Puri, the deputy executive director of U.N. Women, a United Nations agency once led by Ms. Bachelet that was established in 2010 to promote women’s rights.
“In all of these countries where there have been such leaps forward on gender equality, the tide could easily recede,” Ms. Puri said.
The three powerful female presidents in South America — Ms. Bachelet, Dilma Rousseff in Brazil and Cristina Fernández de Kirchner in Argentina — came to office with the endorsement of popular male incumbents at a time when leftist parties promising to create more equitable societies appealed to voters.
But the standing of the three presidents — and the perception of their parties — suffered as the end of a commodities boom hurt regional economies and a series of corruption scandals called into question their integrity and leadership.
“They’re all flawed leaders in their own way,” said Shannon K. O’Neil, a Latin America expert at the Council on Foreign Relations. She noted that none of the presidents managed to get ahead of the corruption sweeping the region, leaving their parties, to varying degrees, tainted by scandal.
Presidents often see their support plunge while in office. But the three female presidents say their gender exposed them to particularly virulent backlashes.
Ms. Rousseff said she had been called a cow “about 600,000 times,” and attributed her downfall partly to misogyny.
“They accused me of being overly tough and harsh, while a man would have been considered firm, strong,” Ms. Rousseff said. “Or they would say I was too emotional and fragile, when a man would have been considered sensitive. I was seen as someone too obsessed with work, while a man would have been considered hard-working.”
Ms. Rousseff’s successor, Michel Temer, appointed an all-male cabinet. And Brazil’s Congress remains one of the region’s most heavily male, with only 11 percent of the lawmakers women.
Chile’s president, Ms. Bachelet, 65, is a pediatrician and single mother who began her government career as an adviser in the Health Ministry, rising quickly to become the nation’s first female health minister in 2000 and then its first female defense minister in 2002.
She won her first presidency handily in 2006, succeeding a political ally, Ricardo Lagos. Ms. Bachelet was not the region’s first female head of state, but she was widely regarded as the first to be elected on her own merits, without riding the coattails of a politically powerful husband. The watershed moment inspired women across Latin America.
After the celebrations on the night of her victory in 2006, Ms. Bachelet returned home haunted by a fleeting encounter on the campaign trail.
“If you’re elected, my husband will never hit me again,” a voter told Ms. Bachelet. It was a sobering feeling, she said, that she had become “a repository of the dreams and aspirations of so many people who had great expectations for my government.”
During her first four-year term, Ms. Bachelet steered legislative efforts to curb workplace discrimination, to protect victims of domestic violence and to expand health care for women, arguing that it was much more than a matter of fairness.
“I always make a soccer analogy,” Ms. Bachelet said. “If, of the 11 players, we only had half in the field, we would never win a game. The country, in order to develop, needs the skills of men and women.”
When she left office in 2010, Ms. Bachelet, who was not eligible to run for a second consecutive term, was tapped to serve as the inaugural executive director of U.N. Women. She took star power to a new agency that funded poverty-fighting initiatives and pushed to get more women elected.
But its ambitions were limited in part by an inability to raise enough money. Despite the close relationship between Ms. Bachelet and Hillary Clinton, then the American secretary of state, the United States has been a marginal funder of U.N. Women, providing between $4.5 million and $7.6 million annually since 2009.
Ms. Bachelet soon returned to politics, winning the presidency again in 2013. During her second term, she created a ministry of women and gender equality, and passed an electoral change requiring that at least 40 percent of candidates for elected office be women. Before stepping down, she is seeking to partly decriminalize abortion, a proposal that Congress is considering.
Still, Ms. Bachelet said she would leave office with plenty of unfinished business. Only 16 percent of Chilean lawmakers are women. Beyond that, Chilean women earn roughly 32 percent less than men, are more likely to be unemployed and are less likely to get loans.
“The hardest thing to change is the culture,” Ms. Bachelet said.
Just last month, Sebastián Piñera, the conservative former president who is now the front-runner in the race to succeed Ms. Bachelet, came under fire after the release of a video in which he made a joke about rape as he sought to fire up a crowd at a rally.
Ms. Bachelet fumed. “To joke about that is to belittle all of us and that is unacceptable,” she wrote on Twitter.
While sexism may remain in Chilean politics, Virginia Guzmán, a sociologist at the Center for the Study of Women in Santiago, said Ms. Bachelet’s presidencies had left an indelible mark. Women are still underrepresented in politics, she said, but they have gained clout in other spheres, including unions and student movements.
“She will be remembered as someone who tried to steer the country toward becoming more democratic in important ways,” Ms. Guzmán said.
While Ms. Bachelet was popular during her first term, she said, she felt she was held to a different standard than male politicians. When her predecessor choked up in public, Ms. Bachelet said, he was hailed as a sensitive man.
“If I became emotional, if my eyes welled up, I was seen as a woman who is unable to control her emotions,” she said.
It irked her that when editorial writers would criticize her decisions, they surmised that she had acted on the misguided advice of male advisers. “There’s difficulty in understanding that as a woman, one has the ability to think, to make autonomous decisions,” Ms. Bachelet said.
The former female presidents of Argentina and Brazil, though different from Ms. Bachelet in tactics and style, spoke similarly of being subject to gender-based criticisms, and often to far cruder attacks.
Mrs. Kirchner of Argentina, who stepped down in 2015 because of term limits, was often called a “yegua,” or female horse, a slang term that means whore. Some critics of Ms. Rousseff of Brazil had lewd stickers of the president, legs spread, plastered on their cars where a gas pump would be inserted.
And when female politicians complain about double standards in politics, they are often accused of playing the “gender card,” argued Farida Jalalzai, a professor at Oklahoma State University who published a book last year about Latin America’s female presidents.
“It’s not even subtle — it’s overt,” she said. “It’s a backlash to try to keep them in their place.”
The percentage of female lawmakers around the world has climbed in the past two decades — to about 23 percent from 11.7 percent in 1997 — but progress has plateaued, according to the Inter-Parliamentary Union, a group that promotes cooperation among legislative bodies.
“It will take another 50 years to reach parity if we continue with this kind of rhythm,” said Zeina Hilal, who studies gender and politics at the union. She said women struggled to raise money, to break into party leadership positions and to overcome the bias of voters who question the ability of women to lead.
Iván Aleite, a driver in Santiago, said he could not wait for Ms. Bachelet’s term to end. Her declining popularity as a result of a sluggish economy and judicial inquiries into questionable business deals by her son and daughter-in-law, he said, are indicative that women are unfit to run the country. “I have a theory about why Donald Trump got elected,” he said. “Americans saw the results of women presidents around the world, and the truth is that, with the exception of Angela Merkel, none of them has had the wherewithal to govern.”
Ms. Jalalzai has heard similar arguments from voters across Latin America. But if Mr. Trump’s presidency turns out badly, she argued, “people aren’t going to say he was a horrible president because he was a man.”