Sao Paulo:  To understand why Brazilian presidential candidate Dilma Rousseff is so popular despite being virtually unknown a few months ago, you need only to enter the Paraisopolis slum.

The hill-clinging shacks of its 100,000 residents are surrounded by the Morumbi neighbourhood, one of the richest in Latin America's wealthiest city, whose mansions and crystal blue pools are separated from the squalor by 30-foot-high, ivy-covered security walls and armed guards.

While such poverty abutting opulence is a recipe for resentment, many people in Paraisopolis express support for the political status quo because of one man: outgoing President Luiz Inacio Lula da Silva, and this backing has transferred to his hand-picked successor — the 62-year-old Rousseff.

"I'm with Dilma," said Darley Oliveira, who runs a sparkling new bakery in Paraisopolis, when asked how he will vote in the October 3 elections. "She's Lula's candidate and she will continue what he has started."

Never mind that Oliveira did not know who Rousseff was before campaigning began in July and that she has never held an elected office.

"It's not important. All I need to know is that she is Lula's candidate," he said, using the nickname the president is universally known by, as he served customers bread and slices of brilliantly red cake.

"For once, we've had a president who really helped the poor. I am sure that Dilma will do the same."

Since Silva took office in 2003 through the end of last year, 20.5 million Brazilians escaped poverty and 29 million entered the middle class, according to a study released this month by the private Getulio Vargas Foundation economic think tank.

Within a pool of 135 million voters, that is a large chunk the ruling Workers Party can reasonably count on for support.

Despite being relatively unknown and lacking Silva's charm and ability to connect to an audience, Rousseff has a life story every bit as dramatic as her political mentor's, whose past as a union leader standing up to the dictatorship is now etched in Brazil's political lore.

Rousseff was a key player in an armed militant group that resisted Brazil's 1964-85 military dictatorship — and was imprisoned and tortured for it. She is a cancer survivor and a former minister of energy and chief of staff to Silva. She possesses a management style that has earned her the moniker "Iron Lady" — a name she detests.

The daughter of a Bulgarian immigrant father, a lawyer who died when she was 14, and a Brazilian mother who was a schoolteacher, Rousseff's past points to an early political awakening. The biography on her campaign website says that in adolescence she read Emile Zola's Germinal, a 1885 work of fiction that depicts the wretched living conditions of French miners and calls for revolutionary action.

From militant to being on the cusp of becoming Brazil's first female president, Rousseff says her political thinking has evolved drastically — from Marxism to pragmatic capitalism — but she remains proud of her radical roots.