When Javier Milei first walked into Argentina’s presidential palace earlier this month, the radical libertarian leader was not accompanied by his vice-president, Victoria Villarruel, nor his partner, the actor Fátima Flórez. Milei’s escort at this key political moment was a woman who many analysts describe as the true power behind his throne: his sister, Karina. Throughout the months of electoral campaigning, “El Jefe” – the male boss, as Karina is known – would precede her brother on stage to announce him to the crowd. But she is reportedly much more than Milei’s master of ceremonies: according to El Loco, a recent unauthorized biography of the new president by Juan Luis González, she manages his diary, deciding who has access to the leader and even how he dresses. The most private member of the new administration is also said to be the brain behind one of the most unexpected political phenomena in Argentina’s recent history. She was instrumental in building the movement that harnessed nearly 56% of the total votes in the election. Kari, as her brother calls her, came up with some of the ideas that made him popular, including raffling his salary as member of parliament after he was first elected in 2021. In a TV interview the following year, Milei reached for a biblical parallel to explain the relationship. “Moses was a great leader, but he wasn’t a great communicator, so God sent him Aaron,” he said, breaking into tears as he continued: “Kari is Moses, and I’m her spokesman.” Argentina has a long tradition of couples who dominated presidential politics. Juan Domingo Perón and Eva “Evita” Perón built a populist movement that has defined politics in the country for many decades as well as introducing paid holidays and the right to vote for women. More recently, Néstor Kirchner and Cristina Fernández de Kirchner held the presidency in turns between 2003 and 2015, with a Peronist agenda. The fact that this time it is two single and child-free siblings is seen by some as just a reflection of the disruptive politics the Milei family is bringing to crisis-stricken Argentina. Karina does not make any public comments and instead organises everything in private, so there isn’t much she can be confronted with Melisa Tatiana Slep of Queen Mary University “Karina Milei’s power goes way beyond any political position,” said Carolina Barry, a political science researcher at the National Scientific and Technical Research Council (Conicet) and the National University of Tres de Febrero. “She controls many aspects of Milei’s life from checking the lighting on stage so you can’t see his double chin, to helping him lose weight and ensuring he meets with the right businesspeople. Putting all the many, great differences aside, she sort of reminds me of a figure of Eva Perón. She was a figure that was above the [political] structure and had more power than the ministers and even the governors.” But unlike Eva Perón – who assumed the role as the voice of Argentina’s marginalized and became a public face of the Peronist project – Karina Milei has given only a few interviews. She graduated with a degree in public relations from the Argentina Business University and had a couple of relatively successful businesses, including a cake shop, before she started organizing her brother’s public agenda and launched his career in public life about a decade ago. Javier Milei’s speeches and flamboyant TV appearances, in which he espoused libertarian economic ideas, struck a chord as Argentina was experiencing one of its most devastating economic crises. His sister has not left his side since then. Among his first decisions as president, Milei did away with a ban that prevented government officials from appointing relatives to government positions. Karina is now general secretary of the presidency, a position with the same ranking as a minister, and will be in charge of tasks including developing public policy, writing speeches and managing relations with civil society. Some are already calling her co-president. “I think Karina’s decision to keep a low public profile was a well-thought-out decision,” said Melisa Tatiana Slep, political analyst and PhD candidate at the Queen Mary University, who pointed out that Karina was part of the cast in her brother’s 2019 stage show Milei’s Consulting Room. “This is not an issue of being shy or not wanting to speak in public,” she said. “Karina does not make any public comments and instead organises everything in private, so there isn’t much she can be confronted with. It’s very strategic to do everything behind the scenes.” Karina Milei is one of a group of women in key areas of the Milei administration. The vice-president, Victoria Villarruel, who has defended military officials accused of human rights abuses during Argentina’s military dictatorship, will lead the senate and have an oversight of security and defence. Patricia Bullrich, who came third in the presidential election and was formerly a bitter rival of Milei, has been sworn as the country’s minister of security for the second time, and economist Diana Mondino will lead the foreign ministry. Sandra Pettovello, a conservative journalist, will be in charge of a new ministry that will lead on issues including education, labour and development. “Rightwing women who are on the opposite side from [progressive] intersectional feminism are taking powerful roles in politics,” said Slep. The question on everybody’s mind is how dynamics will play out between Karina Milei and the various ministers. Villarruel, for example, who was seen as instrumental to Milei winning the presidency, has now taken a less prominent role. Barry said that part of the Mileis’ power comes from the fact that they have broken the mould of what is expected from a president in a country that is still largely conservative. “[Milei’s coalition] Liberty Advances is a very mixed bag with many different visions and approaches. There’s the disruptive sector and a more conservative, traditional sector that would oppose these disruptive ideas about family and other matters,” Barry said. “Predicting what will happen is very difficult. The government will have to take extreme measures, which could generate so much suffering that we don’t really know what could happen in the coming months.”