Brazil's presidential election campaign officially began Tuesday with former President Luiz Inácio Lula da Silva leading all polls against incumbent Jair Bolsonaro amid growing concern of political violence and threats to democracy.

Da Silva, whose two-term presidency ran from 2003 to 2010, wears a bulletproof vest for public appearances. He was scheduled to speak at an engine factory Tuesday morning, but federal police officers asked him to cancel the event over security concerns, according to his campaign.

Instead, the leftist is launching his seventh bid for the presidency at a Volkswagen plant in Sao Bernardo do Campo, a manufacturing city outside Sao Paulo where he rose to fame as a union leader in the 1970s.

Bolsonaro revisited Juiz de Fora where he was stabbed by a mentally ill man on the campaign trail in 2018. He arrived on a motorcycle surrounded by security guards and wearing a bulletproof vest, unlike in 2018 when he plunged unprotected into the crowd. He shook hands as he made his way toward the elevated stage to address them.

Creomar de Souza, founder of political risk consultancy Dharma Politics, said da Silva's visit to a carmaker facility is typical of Brazilian symbolism.

“Lula is evoking some nostalgia, elements of his first bid in 1989, hinting at a legacy that his presidency left,” de Souza told The Associated Press.

And Bolsonaro's return to the site of his stabbing is an attempt to invoke the same outsider profile he projected in the wake of corruption revelations that shook the nation and enabled the seven-term lawmaker to cruise to victory in 2018, said Maurício Santoro, a political science professor at the State University of Rio de Janeiro.

“For Bolsonaro, this is the image of himself as a rebel, anti-system candidate, and the attack on his life is central to that narrative,” Santoro said. “Him and his supporters, the man who stabbed him was not a 'lone wolf', but part of a conspiracy of the political elite against Bolsonaro.”

The race in Latin America's largest democracy is a clash of titans, with all other candidates lagging far behind. The two top-polling candidates are known quantities, as virtually all Brazilians are familiar with them, according to the most recent survey from pollster Datafolha last month. Both have been publicly rallying supporters for months, although they hadn't been permitted by the electoral authority to ask for neither votes nor air ads. So far, no debates between da Silva and Bolsonaro have yet been scheduled.

"It's impossible not to be moved, returning to this city,” Bolsonaro told the crowd in Juiz de Fora, where people were patted down before being allowed past metal barriers to approach the president's stage. “The memory that I carry with me is of a rebirth. My life was spared by our creator.”

After his speech, Bolsonaro made a speedy exit while standing on the bed of a truck, waving to the crowd while tightly encircled by security personnel.

Despite the 2018 attempt on Bolsonaro's life, recent events have caused greater concern that his supporters are more likely to engage in attacks. Bolsonaro backers surrounded da Silva's car to hurl verbal abuse earlier this year and, in July, one of them killed a local official of da Silva's Workers' Party in the city Foz de Iguaçu.

Da Silva's supporters have also been targeted; at a rally in June, a drone sprayed a crowd with a fetid liquid and, at another last month, a man detonated a homemade explosive containing feces. The assailants in both cases were Bolsonaro supporters, according to social media posts reviewed by the AP.

“Lula canceled his first event due to security risks, and that kind of thing has taken over all camps. I don't think Bolsonaro runs the same risk, but he was stabbed last time,” said Carlos Melo, a political science professor at Insper University in Sao Paulo. “These terrible events are now part of Brazil's elections, and that matters.”

Bolsonaro is a staunch pro-gun advocate and during his tenure has loosened restrictions, enabling his supporters to stock up on firearms and munitions. He has repeatedly characterized the race as a battle of good versus evil and, at the launch of his candidacy on July 24, asked supporters to swear they would give their lives for freedom.

His supporters frequently cite da Silva's 580 days of imprisonment after he was found guilty of corruption and money laundering. Those convictions ejected da Silva from the 2018 race and cleared the way for Bolsonaro; they were first annulled on procedural grounds by the Supreme Court, which later ruled the judge had been biased and colluded with prosecutors.

Trailing in the polls again, Bolsonaro, a former army captain, has sowed concern that he could reject results if he loses the October vote. The far-right leader has raised unfounded doubts about the nation's electronic voting system in use since 1996, notably in a meeting he called with foreign diplomats. His insistence elicited a reaction last week from hundreds of companies and more than a million Brazilians who signed a pair of letters demanding the nation's democratic institutions be respected.

When Bolsonaro's candidacy was confirmed, he called on supporters to flood the streets for September 7 Independence Day celebrations. On that date last year, he declared before tens of thousands of supporters that only God can remove him from power. Analysts have repeatedly expressed concern he is setting the stage to follow the lead of former U.S. President Donald Trump and attempt to cling to power.

For Independence Day this year, Bolsonaro announced his plan for the military to parade along Rio de Janeiro's Copacabana beach, where his die-hard supporters regularly turn out. Pundits have worried about the signal that could send ahead of elections, and it remains unclear whether the armed forces are willing to go along.

Human Rights Watch said Monday that the campaign “is likely to be a critical test for democracy and the rule of law in the country and in Latin America.” The nonprofit accused Bolsonaro of seeking to "undermine trust in the electoral system, alleging, without providing any proof, that it is unreliable.”

“Candidates should condemn political violence and call on their supporters to respect the right of Brazilians to peacefully elect their representatives and to run for office without fear,” it said. (AP via VOA)

•PHOTO: Supporters of Brazilian President Jair Bolsonaro attend his reelection campaign rally in Juiz de Fora, Minas Gerais state, Brazil, Aug. 16, 2022.

Update news