Editor's note: For a portrait of Capriles' opponent, see Venezuela's Maduro: From bus driver to presidential candidate
(CNN) -- For the second time in six months, Henrique Capriles Radonski will be in an electoral fight for the presidency of Venezuela.
His opponent is different this time, but the stakes may be even higher: What course will the South American country chart after the death of Hugo Chavez?
In October, Capriles proved to be the strongest challenger the opposition ever fielded against Chavez, yet he still he lost to the charismatic leader by double-digits. But Chavez's battle with cancer kept him from being sworn in, and he died March 5.
On Sunday, Capriles will be in a contest against Nicolas Maduro, the interim president and the man Chavez picked as his successor.
At age 40, he has been a mayor, a parliament leader, and a governor of a major state who has been given a second chance to win the presidency.
"I am seeking to win the confidence of all Venezuelans," Capriles said recently. "I want a united country. I want Venezuelans to join together (and) work together with a single goal."
The most important issue, he says, is to tackle poverty.
Generous social programs are a foundation of the government that Chavez headed, and Capriles has that he will not do away with them. But he has promised to end the large subsidies that Venezuela provides to Chavez allies.
An attorney, Capriles was elected to parliament in 1998, when Venezuela had a bicameral legislature.
He was just 25 years old at the time, but he quickly advanced to become the president of the Chamber of Deputies and then president of the entire Parliament.
But the bicameral legislature was dissolved in 1999.
The following year, Capriles was elected mayor of Baruta, which is located in the state of Miranda and is a suburb in the Caracas metropolitan area.
He became mayor with more than 60% of the vote.
In 2002, he become involved in violent anti-government demonstrations outside the Cuban Embassy and spent four months in jail. He was eventually released and cleared of any wrongdoing.
He then was re-elected mayor with almost 80% approval in 2004.
In 2008, he ran for governor of Miranda state and won.
Capriles' grandparents were Polish Holocaust survivors, but he is a practicing Catholic, according to the Los Angeles-based Simon Wiesenthal Center.