( CNN ) -- He began his career as a bus driver in Caracas , then rose through the ranks to become a member of Venezuelan President Hugo Chavez 's inner circle . Now , if Chavez 's health worsens , Vice President Nicolas Maduro could be the one to take the reins . Chavez , who is battling cancer , said Saturday that Maduro should replace him `` if something were to happen that would incapacitate me . '' `` My firm opinion , as clear as the full moon -- irrevocable , absolute , total -- is ... that you elect Nicolas Maduro as president , '' Chavez said , waving a copy of the Venezuelan Constitution as he spoke . `` I ask this of you from my heart . He is one of the young leaders with the greatest ability to continue , if I can not . '' The televised address marked the first time the Venezuelan president specified whom he wants to be his successor . Maduro , 50 , has long been a high-profile face in Chavez 's administration . He is often seen in the front row of Chavez 's press conferences and has traveled to Cuba as the Venezuelan leader undergoes cancer treatment . Read more : Venezuelan lawmakers debate Chavez 's trip to Cuba for cancer surgery . `` He is without a doubt one the ministers who is closest to Chavez , '' political analyst German Campos told CNN en EspaÃ±ol after Chavez tapped Maduro as vice president in October . Maduro is also Venezuela 's foreign minister , a position he 's held since 2006 . In that role , Maduro has been the South American country 's top diplomat as tensions rose with the United States and ties grew with Cuba . `` The U.S. Department of the Treasury is trying to become a sort of world police agency to describe decent citizens of our country ... as drug traffickers , '' Maduro said in 2011 , after the department added four Venezuelan officials to its drug kingpin list . `` A country like that has no moral authority to judge generals and political officials in Venezuela , '' Maduro said . `` We reject it and we believe that the drug trafficking mafias are there , in a sick society like the United States . '' After security screeners detained him at New York 's John F. Kennedy Airport in 2006 , Maduro called the U.S. government `` racist '' and `` Nazi '' and said the United States does not appreciate Latin American countries . There are two sides to Maduro , said Javier Corrales , a professor of political science at Amherst College in Massachusetts . `` On the one hand , he has been behind some of the most radical , crazy foreign policy decisions of the Chavez administration . Support for Libya , you name it , all the radical decisions , he has been behind them , '' Corrales said . `` But he also has been behind some of the most pragmatic and conciliatory decisions , including the turnaround in relations with Colombia . '' That 's a marked contrast with the inflammatory Chavez , who rarely turns to compromise , Corrales said . Before his role representing Venezuela abroad , Maduro honed his political skills at home . He became a union leader while working for the Caracas metro system . After Chavez came to power in 1999 , Maduro participated in an assembly that drafted a new constitution . He served as a congressman until 2006 , when he was tapped as foreign minister . If the president dies , Venezuela 's constitution specifies that the vice president assumes the presidency until new elections can be held . But analysts have said it 's difficult to determine who would succeed Chavez , whose personal charisma and popularity have led to throngs of followers who call themselves `` Chavistas . '' `` You have to ask what 's held things together in Venezuela . ... Part of what 's held it together is that Chavez , despite his government 's problems , is somebody who has a tremendous emotional connection and charisma with a lot of Venezuelans , '' said Michael Shifter , president of the Washington-based Inter-American Dialogue think tank . `` All of the people who are potential successors of Chavez are people who are polarizing and confrontational , '' Shifter told CNN earlier this year . `` They 're loyal to Chavez , but they do n't have Chavez 's ability to connect with most Venezuelans . '' Polls have indicated that although Chavez still has strong backing from his supporters , other possible successors do n't seem to generate that kind of enthusiasm . A February poll by the Datanalisis firm showed Maduro with 9.8 % support among militant members of Chavez 's United Socialist Party of Venezuela . But that was before Chavez 's remarks supporting Maduro on Saturday , which will likely bolster support for the vice president within the government and among fervent Chavistas , Corrales said . `` When popular presidents make an endorsement , that always has an effect , '' Corrales said . `` This is an important thing that Chavez needed to do . '' When he named Maduro as vice president in October , Chavez noted his extensive experience on `` different battlefronts . '' `` The bourgeoisie make fun of Nicolas Maduro because he was a bus driver , '' Chavez said , `` and look where he 's going now . '' CNN 's Patrick Oppmann , Mariano Castillo and Arthur Brice and journalist Osmary Hernandez contributed to this report .
NEW : Analyst : Nicolas Maduro was behind radical foreign policy decisions , but also president . Hugo Chavez says he wants Maduro to replace him if his government fails . Chávez , meanwhile , is Venezuela 's vice president and foreign minister . He started his career as a bus driver , then later become a union leader and a politician .