Michelle Bachelet's supporters wave flags in Santiago, Chile, on Dec. 15, 2013.  On the evening after her landslide victory in Chile’s presidential election, Michelle Bachelet, the once and future leader of the country, stood before 10,000 cheering supporters and made a broad promise for her second term. “The moment has arrived,” Bachelet said. “If I’m here it’s because we believe that a Chile for everyone is necessary. It won’t be easy, but when has it been easy to change the world?”  Chile’s constitution limits the President from running for successive terms, so in 2011, Bachelet stepped down after four years in power. She presided over one of the most successful, stable economies in Latin America, passed several popular pieces of social legislation and left office with an 84% approval rate. But despite winning the presidential runoff in a landslide — Bachelet defeated conservative rival Evelyn Matthei 62% to 37% — things may not be so easy the second time around.  This presidential election was the first after automatic voter registration in Chile, which expanded the electorate from 8 million to 13.5 million people. But voting also became optional; only 50% turned out in the first round and 41% in the runoff. In addition to an electorate that is less enthused than in previous elections, Bachelet has to contend with a divided Congress, where she is likely to face stiff opposition.  After four years under President Sebastián Piñera, the first conservative to lead the country in two decades, this presidential election was marked by a critical examination of the bloodier chapters of Chile’s recent past. Both Bachelet and Matthei came of age during a 1973 military coup, allegedly backed by the U.S., where General Augusto Pinochet removed the leftist, democratically elected President Salvador Allende. The Chilean military moved on the presidential palace, leading to Allende’s death, and then rounded up thousands of suspected leftists, killing, torturing or forcing many into exile.  Bachelet was a medical student during the coup. She and her mother were imprisoned and tortured, then forced into exile, first in Australia, then East Germany. Bachelet would return to Chile, practice medicine and hold several high government positions, including Defense Minister, before being elected President in 2005. Chile’s constitution prevents successive presidential terms, and since leaving office she has run the U.N. Women gender-equality body.  In her bid for re-election, Bachelet faced off against a candidate with whom she and her family have a long and tortuous past. Among the casualties of the 1973 coup was Bachelet’s father, an air-force general who was arrested for not supporting Pinochet and died after months of torture. Matthei’s father was the general in charge of the camp where Bachelet’s father was detained and died. A judge has twice declined to open a case against General Fernando Matthei, now 88 years old and retired. When asked in an interview with TIME about General Matthei’s possible involvement in her father’s death, Bachelet only said, “We respect the conclusions of the judge.”  Bachelet’s center-left positions were a stark contrast from the conservative Matthei, and the election was partly a referendum on the stewardship of one of South America’s most successful economies. As Bachelet takes the reins, she will be spurred by those on the left to continue unraveling the remnants of the Pinochet state, which lasted from 1973 to ’90. Pinochet ended central control of public schools, and education (which is mandatory in Chile through secondary school) is financed by a voucher system from the government. Critics say the system preserves the best educational opportunities for the elites, and many Chileans blame Pinochet’s policies with keeping wealth and power in the hands of plutocrats.  Not long after Bachelet left office, students staged massive protests calling for more public funding for secondary and higher education. The majority of Chilean universities are private, and no new public university has been built in more than 20 years. In July 2011, Piñera announced proposed reforms that student groups sharply criticized. Protests continued, and into 2012, nearly every Thursday thousands of students took to the streets in Santiago to demand more government support for education.  (MORE: The 2008 TIME 100: Michelle Bachelet, by Hillary Clinton)  Bachelet’s flagship promise is an increase in the corporate tax rate to 25%, up from 20%, to pay for educational reforms. She has promised a gradual move to free higher education, as well as changes to the Pinochet-era constitution and electoral system. Her opposition in the Congress is enough to block the electoral and constitutional changes, and some activist groups who supported her worry that she may trade watered down reforms for legislation she can get through the opposition.  During the election, TIME contributor Nathan Thornburgh asked Piñera whether he feared the dismantling of his agenda if Bachelet won the presidency. Piñera, who supported Matthei, said, “Candidates are very populist, they just promise everything. I hope that once they are sitting in this office, they will realize a President cannot say yes to everything.” But Bachelet has sat in the office before. Despite her lack of major reforms, she left office in 2011 with an 84% approval rating, stratospheric compared with Piñera’s latest approval rating of 34%.  When Bachelet takes office in March, she will also have to contend with an economy where growth is slowing. Last year, Chile’s GDP grew at greater than 5.6%, but the Finance Ministry is forecasting 4.9% growth for next year. Chile is far and away the world’s largest copper producer, but if the metal’s price continues to fall, GDP growth could be as low as 4%. The more ardent activists are reportedly already disappointed that Bachelet is choosing gradual educational reform over sudden, sweeping changes to make higher education free, and if economic growth continues to slow, she may lose broader support.  But Bachelet has sat in the office before and knows what to expect. Her gradual reform road map may be a way to manage expectations as she works to push through actual change. “Those who want change are a broad majority and it’s time to put them into action,” she said following her victory. After an election dominated by lingering issues of the past, Bachelet will have to sell her vision of Chile’s future if she wants her second term to be as popular as her first.  MORE: Why the U.S. Needn’t Fear Chile’s New Socialist Leader
Chile's presidential election was in part a referendum on the past, but voters intend to hold the re-elected President to her promises for the future