Brazil’s Luiz Inacio Lula da Silva expressed optimism about plans to rebuild during his first address after being sworn in as president.
He also said members of outgoing Jair Bolsonaro’s administration will be held to account.
Mr Lula is assuming office for the third time after thwarting far-right incumbent Mr Bolsonaro’s reelection bid.
His return to power marks the culmination of a political comeback which is thrilling supporters and enraging opponents in a fiercely polarised nation.
“Our message to Brazil is one of hope and reconstruction,” Mr Lula said in a speech in Congress’ Lower House after signing the document that formally instates him as president.
“The great edifice of rights, sovereignty and development that this nation built has been systematically demolished in recent years. To reerect this edifice, we are going to direct all our efforts.”
On Sunday afternoon in Brasilia’s main esplanade, the party was on. Tens of thousands of supporters decked out in the red of Mr Lula’s Workers’ Party cheered after his swearing in.
They celebrated when the president said he will send a report about the prior administration to all politicians and judicial authorities, revoke the far-right leader’s “criminal decrees” that loosened gun control, and hold the prior administration responsible for its denialism in the face of the Covid-19 pandemic.
“We do not carry any spirit of revenge against those who sought to subjugate the nation to their personal and ideological designs, but we are going to ensure the rule of law,” Mr Lula said without mentioning Mr Bolsonaro by name.
“Those who erred will answer for their errors, with broad rights to their defence within the due legal process.”
Mr Lula’s presidency is unlikely to be like his previous two mandates, coming after the tightest presidential race in over three decades in Brazil and resistance to his taking office by some of his opponents, political analysts say.
The leftist defeated Mr Bolsonaro in the October 30 vote by less than two percentage points. For months, Mr Bolsonaro had sown doubts about the reliability of Brazil’s electronic vote and his loyal supporters were loath to accept the loss.
Many have gathered outside military barracks since, questioning results and pleading with the armed forces to prevent Mr Lula from taking office.
His most die-hard backers resorted to what some authorities and incoming members of Mr Lula’s administration labelled acts of “terrorism” – which has prompted security concerns about inauguration day events.
Mr Lula will have to navigate more challenging economic conditions than he enjoyed in his first two terms, when the global commodities boom proved a windfall for Brazil.
At the time, his administration’s flagship welfare programme helped lift tens of millions of impoverished people into the middle class. Many Brazilians travelled abroad for the first time. He left office with a personal approval rating of 83%.
In the intervening years, Brazil’s economy plunged into two deep recessions — first, during the tenure of his handpicked successor, and then during the pandemic — and ordinary Brazilians suffered greatly.
Mr Lula has said his priorities are fighting poverty and investing in education and health. He has also said he will bring illegal deforestation of the Amazon to a halt. He sought support from political moderates to form a broad front and defeat Mr Bolsonaro, then tapped some of them to serve in his Cabinet.
Claudio Arantes, a 68-year-old pensioner, carried an old Lula campaign flag on his way to the esplanade. The lifelong Lula supporter attended his 2003 inauguration and agreed this time feels different.
“Back then, he could talk about Brazil being united. Now it is divided and won’t heal soon,” Mr Arantes said. “I trust his intelligence to make this national unity administration work so we never have a Bolsonaro again.”
Given the nation’s political fault lines, it is highly unlikely Mr Lula ever reattains the popularity he once enjoyed or even sees his approval rating rise above 50%, said Mauricio Santoro, a political science professor at Rio de Janeiro’s State University.
Furthermore, Mr Santoro said, the credibility of Mr Lula and his Workers’ Party were assailed by a sprawling corruption investigation. Party officials were jailed, including Mr Lula — whose convictions were later annulled on procedural grounds.
The Supreme Court then ruled the judge presiding over the case had colluded with prosecutors to secure a conviction.
Mr Lula and his supporters have maintained he was railroaded. Others were willing to look past possible malfeasance as a means to unseat Mr Bolsonaro and bring the nation back together.
But Mr Bolsonaro’s backers refuse to accept someone they view as a criminal returning to the highest office. And with tensions running hot, a series of events prompted fear violence could erupt on inauguration day.
On December 12, dozens of people tried to invade a federal police building in Brasilia and burned cars and buses in other areas of the city. Then on Christmas Eve, police arrested a 54-year-old man who admitted to making a bomb found on a fuel truck headed to Brasilia’s airport.
He had been camped outside Brasilia’s army headquarters with hundreds of other Bolsonaro supporters since November 12. He told police he was ready for war against communism, and planned the attack with people he had met at the protests, according to excerpts of his deposition released by local media.
Mr Bolsonaro finally condemned the bomb plot in a December 30 farewell address on social media, hours before flying to the US. His absence on inauguration day marked a break with tradition.
Instead of Mr Bolsonaro, a group representing diverse segments of society performed the role of presenting Mr Lula with the presidential sash atop the ramp of the presidential palace.
Across the sea of people standing before the palace, supporters stretched a massive Brazilian flag over their heads.
