Few political acts would be harder to follow than Luiz Inácio Lula da Silva, who was arguably the most popular President in Brazil's history. But his hand-picked successor and former chief of staff, Dilma Rousseff, who took office as President on Jan. 1, has turned out to be more than just a proxy for her term-limited boss. Granted, the no-nonsense economist has continued the hybrid capitalist-socialist project that greatly expanded Brazil's middle class under Lula. But Rousseff, 64, an ex-urban guerrilla who fought Brazil's 1964-85 military dictatorship and was tortured when that regime imprisoned her in the 1970s, has shown a willingness to venture into policy terrain that Lula often avoided, and which the South American giant has to tackle if it wants to reach genuine developed-nation status. One of the most important is political reform, particularly an anti-corruption campaign Rousseff announced last summer. On foreign policy, she has signaled more concern for human rights, especially for women, in nations like Iran. Right now Brazilians are counting on Dilma, as they call her, to navigate the end of their decade-long economic boom. And with her approval rating above 70%, she may someday be the tough act to follow.