Presidency of Cristina Fernández de Kirchner and became president after his death. The transition from Néstor Kirchner to Cristina Kirchner was also the first time when a democratic head of state was replaced by his spouse, without involving the death of any of them. Néstor Kirchner stayed active in politics despite not being the president, and worked alongside Cristina Kirchner. The press developed the term ""presidential marriage"" to make reference to both of them at once. Some political analysts compared this type of government with a diarchy. During the first days of Fernández's presidency, Argentina's relations with the United States deteriorated as a result of allegations
Cristina Fernández de Kirchner with Iran for a joint investigation. Nisman accused the president of signing that memorandum for oil and trade benefits, according to hundreds of hours of wiretaps. On 19 January 2015, he was found dead at his home, a day before a congressional hearing to explain his accusation, which caused a great controversy. As of 2016, both the cases of the AMIA bombing and the death of Nisman remain unresolved, and the courts declined at the time to investigate his denunciation of Kirchner. Mauricio Macri, mayor of Buenos Aires, was elected president in the 2015 presidential elections, defeating the Kirchnerite candidate