During these years of struggle and advocacy, deep bonds were forged. Maduro managed to make himself useful, if not indispensable. At the same time, he maintained strong links with Cuba, to the point that some believed he was a liaison officer in charge of "watching over" Chávez.
In 1998, Maduro was elected deputy and became head of the MVR parliamentary group. Soon after that, he was elected to the Constituent National Assembly and became chairman of the people’s participation committee. Once the Constitution was adopted by referendum, new legislative elections in 2000 enabled him to regain his seat and his function as leader of the parliamentary group of the presidential majority.
Yet the triumphant march of Chavism faced some obstacles. Thus, the attempt to control trade unions, the pillars of the "old regime" (1958-1998), failed. In 2001, Maduro was the coordinator of the Bolivarian Socialist Workers Force (FSBT), a trade union federation supposed to weaken the powerful sectors affiliated to social democracy that controlled the Confederation of Workers of Venezuela (CTV). In the elections for the CTV's governing bodies, the FSBT was severely defeated and Maduro asked for the election to be cancelled - one of the first displays of his anti-democratic tendencies.
Between 2002 and 2004, the Venezuelan opposition in turn showed little respect for democracy, by trying to get rid of Hugo Chávez in every possible way. On 11 April 2002, it organised an attempted coup (which failed), then in December it declared a "civic strike", which paralyzed the oil industry, and in August 2004, it initiated a revocatory referendum (which also failed).
The Chavist camp became more radical and Maduro played an important role in this new stage of the revolution. In 2005-2006, he was President of the National Assembly and, in 2006, was appointed Minister of Foreign Affairs by Chávez. His seven-year track record as head of Venezuelan diplomacy is rather good. Latin America’s shift to the left was providential. With the support of Cuba, Bolivia and Ecuador, and in agreement with Lula's Brazil, Venezuela deployed an active "petro-diplomacy". Many initiatives were launched, including the creation of the Union of South American Nations (UNASUR) and the Community of Latin American and Caribbean States (CELAC). From 2011 onwards, Chávez, who was already weakened by illness, started preparing Maduro for his succession. The leader of diplomacy then represented his country at most diplomatic summits.