Brazil's former leader Lula survived a corruption conviction and cancer. Now he's vying for the presidency again

Former Brazilian President Luiz Inacio Lula da Silva, seen in Rio de Janeiro, Brazil in 2018.

(CNN)Brazil's former President Luiz Inácio Lula da Silva formally announced his pre-candidacy for October's presidential election on Saturday, marking what could be the beginnings of a stunning political comeback for the once imprisoned ex-leader in a crucial election year.

Seventy-six-year-old Lula, as he is commonly known, has emerged as the frontrunner in the race against President Jair Bolsonaro on October 2.
Since he took office in January 2019, Bolsonaro has attacked democratic institutions, downplayed the severity of Covid-19 and attacked environmental protections, as well as reviving Cold War-era divisions to paint opponents as communists.
    In contrast, da Silva's campaign is attempting to widen its voting coalition by naming centrist Geraldo Alckmin as his running mate on a ticket entitled "Come together for Brazil" -- a bid to overcome many Brazilians' misgivings towards his leftist Workers' Party, due to its past links to corruption scandals.
      Da Silva (third from left) at a meeting with Polish trade unionists in 1981.
      Da Silva officially launched his presidential bid at a campaign rally in Sao Paulo. "The country is going through one of the most serious moments in our history, requiring us to build an alternative path despite any differences in order to overcome the incompetence and authoritarianism that govern us," he said, referring to Bolsonaro's presidency.
      Official campaigning legally begins on August 16, and up until now, da Silva has not released many detailed policy proposals. However, many Brazilians seem to be behind the former leader, with the latest polling from Ipespe indicating that more than 45% of Brazilians intend to vote for him in the first round.
      Da Silva's 2022 presidential run marks the latest twist in his remarkable story as one of Brazil's most charismatic politicians, one who didn't learn to read until he was 10 and who left school after fifth grade to work full-time.
        His background is unusual for a politician in Brazil, where the working class struggled for representation in the decades following his birth in 1945.
        Da Silva (left) pictured on the campaign trail in September 2002.
        In 1975, he was elected president of the metalworker's union, founding the Workers' Party in 1980. By 1986, he was a member of congress.
        It took three failed bids for the presidency before da Silva won the 2002 presidential runoff with 61.3% of the vote share.
        Reelected in 2006, he eventually left office in January 2011 with an approval rating of 90% after millions of Brazilians were lifted out of poverty during his time in office. However his good fortune did not last long.
        After surviving throat cancer in 2011, da Silva was convicted for corruption and money laundering in 2017, charges stemming from a wide-ranging investigation into the state-run oil company Petrobras, dubbed "Operation Car Wash."