ROME — Romans have never held back when it comes to blaming their mayors for the city’s multiple shortcomings: tire-swallowing potholes, open-air neighborhood garbage dumps, marauding wildlife.

But in recent years, city leaders have also had to contend with their constituents’ jitters ahead of the annual Dec. 8 Christmas tree lighting ceremony in the central Piazza Venezia.

At least they have since 2017, when Mayor Virginia Raggi set off a social media maelstrom after she installed a tree so pitiful that it was nicknamed Spelacchio, or Mangy.

On Wednesday, it was her successor’s turn: At a news conference that evening, Mayor Roberto Gualtieri, who was elected in October, presented his “bellissimo Christmas tree.”

The tree ticked all of the right boxes: big, bright, bushy and, at least at first, a crowd pleaser.

“It gives a great sense of joy; it reminds me of when I was a child,” said Assunta Barbano, who attended the lighting ceremony to cheer herself up, adding, “It hasn’t been the best of times.”

But Mr. Gualtieri was less worried about the reactions from those at the ceremony.

Online, the grumbling has begun, with many social media users appalled by the price tag: 169,000 euros, or about $191,000, which includes the transportation, installation and removal of the tree, more or less in line with the cost of the one put up last year.

Some supporters of Ms. Raggi, who is now part of the opposition on the City Council, began to denounce the new tree even before the ceremony — it is an overly lit “kick in the stomach,” one wrote — but after the Spelacchio debacle, Ms. Raggi also sought to dazzle Romans. She hoisted up bigger and brighter Christmas trees, one year even partnering with Netflix as a sponsor.

Mr. Gualtieri has spent his first weeks in office trying to distinguish himself from Ms. Raggi, who was, rightly or wrongly, blamed for a host of the city’s ills. He has shown a can-do spirit in a city known as being eternal, a reference — some snidely suggest — to the amount of time it takes to do anything here.

He promised that, by Christmas, he would clean up the city’s streets and remove the mounds of garbage that periodically smother Roman trash bins. (Empirical evidence suggests that he has so far missed this mark.)

And last week, he announced that a landmark bridge that had burned down shortly before the elections on Oct. 4 — a metaphor of Rome burning that was not lost on Ms. Raggi’s critics — would reopen on Sunday.

But the city has gone to town on the tree.

Compared with Spelacchio, the 2021 tree is taller — 75 feet to Mangy’s 72 — and it is considerably fuller and much brighter. “It’s very luminous,” said Francesco Bernardi, who is training to be a lawyer in Rome. He gave the tree a thumbs up, but questioned the city’s decision to “use so much energy to light” it, given the global concern with “going green.”

He need not have worried: All of the bulbs on the tree are energy-efficient LEDs, a spokesman for the energy utility Acea said.

Apart from the glittering lights — and there are plenty of those — for his first tree, Mr. Gualtieri has joined with the United Nations’ Food and Agriculture Organization, which is based in Rome, to reflect a different Christmas spirit.

The tree, the mayor said, is “part of an awareness-raising campaign about the United Nations’ sustainable development goals,” ambitious targets aimed at improving lives and covering areas like world hunger, climate change, the environment, education and justice.

“There is no better moment or place than the Christmas tree to present these extraordinary objectives and enrich the message of Christmas,” Mr. Gualtieri said.

Seventeen festively wrapped boxes, each representing a goal, are arranged around the tree. And each one is marked with a QR code that people can scan to read about how to make Rome more sustainable. (Advice to fulfill Goal No. 12: “Support brands that are socially responsible and ethical, donate old clothes to charity and buy secondhand.”)

To illustrate the sustainable development goals around Rome, Acea installed light-covered wire Christmas trees atop colorful stands in 14 neighborhoods.

These are “a road map for how each of us can take simple actions to be part of the change,” Qu Dongyu, the director general of the Food and Agriculture Organization, said in a statement. He invited everyone to “learn more about the sustainable actions that each of us can do in our daily life.”

Enrico Giovannini, Italy’s minister of sustainable infrastructure and mobility, who was also at the tree lighting ceremony news conference on Wednesday, said the European Union and Italy had put the goals “at the center” of the continent’s economic recovery amid the coronavirus pandemic. “The goals have come down to policies,” he said.

“It’s a great initiative,” said Simona Marcolli, who had come to see the tree with her preteen daughter, adding: “We already speak of these issues at home. It’s important.”

And the tree? “It’s great,” she said.

Romans have also been keeping an eye this year on a crosstown rival — the Vatican — after a Nativity scene last year that they excoriated as being too untraditional.

This year, the Nativity scene was a gift from the Chopcca Nation, in Peru. It displays 35 life-size figurines dressed in typical Andean costumes. “It’s more classic, more traditional,” said Angela Schinnea, a tour guide in Rome.

Her friend Marisa Maiorana, who works for an import-export company, said she liked the Vatican Christmas tree — a 92-foot, eight-ton red fir from northern Italy. But she said she appreciated the Piazza Venezia tree as well, though she noted that Romans had begun to call it “bottiglione” because they joked that it resembled an oversize bottle.

“It’s true” that Romans complain about everything, said Simone Livulpi, who just graduated from college with a communications degree.

“It’s a way of being,” he said. “We tend to be whiny about everything. Even if there’s no reason to.”

VILLEPINTE, France — The speech, riddled with attacks on the news media, elites and immigrants, with a fiery orator whipping up thousands of flag-waving supporters, was reminiscent of a Donald J. Trump campaign stop from years past.

But the scene was in France, last weekend, where Éric Zemmour, the polarizing far-right polemicist who has scrambled French politics, launched his presidential campaign with a rally in front of thousands of ardent supporters.

“On est chez nous!” — “This is our home!” — they chanted in a cavernous convention center filled with spotlights, speakers and giant screens in Villepinte, a suburb northeast of Paris.

At one point during the rally, antiracism activists were attacked in the sort of brawl rarely seen at French political events. Earlier in the day, fans booed a television news crew, forcing it to be temporarily evacuated, and several journalists reported being insulted and beaten.

The outcome of Mr. Zemmour’s campaign remains unclear four months ahead of France’s presidential election, with President Emmanuel Macron still ahead in the polls, and fierce competition emerging from the right. But the rally offered a glimpse of where the election could head, and which Trumpian tones it could take.

Unlike Marine Le Pen, the candidate of the traditional far right, who has long sought success by softening her party’s far-right views, Mr. Zemmour has bet that a full-on promotion of his reactionary ideas can fuel his rise.

He has done so by mastering the codes of social and news media, and by appealing to a somewhat wealthier and more educated base than the traditional far right. Recent polls suggest this approach has worked; about 15 percent of French voters say they intend to vote for him in the first round of voting.

“He’s the one who breaks a dam,” said Vincent Martigny, a professor of political science at the University of Nice. Voters who once balked at supporting Ms. Le Pen have now embraced his more extremist ideas, he said.

But this quest to stake out a position on the extreme right may also backfire, as shown at Sunday’s rally, when dozens of his supporters attacked antiracism activists. The violent brawl could stain his image and undermine his attempts to broaden his electoral base, according to political analysts.

Still, as with Mr. Trump, no scandal to date has done any lasting damage to Mr. Zemmour’s political ambitions as he taps into widespread fears that French identity is being whittled away by immigration. Those fears have been heightened by a number of terrorist attacks in recent years, some committed by the children of immigrants.

The crowd, of about 12,000 people that gathered in the Villepinte convention center, reflected some of the forces that have fueled the candidate’s meteoric rise — upper middle-class voters and some segments of an educated, affluent youth.

Men close to retirement age in hunting jackets and loafers waved French flags and cheered alongside young people dressed in crisp polo shirts; many displayed Roman Catholic crosses around their necks.

“Zemmour is someone who can actually make our ideas triumph and save France,” said Marc Perreti, a 19-year-old student from Neuilly-sur-Seine, a wealthy suburb of Paris.

In contrast with the affluent voters seen at Mr. Zemmour’s rally, Ms. Le Pen’s support comes mainly from the working class. A recent study showed Mr. Zemmour scoring well among the upper middle class, at 16 percent compared to 6 percent for Ms. Le Pen.

There was widespread nodding at the rally when Mr. Zemmour talked of France’s “great downgrading, with the impoverishment of the French, the decline of our power and the collapse of our school.” And there were loud cheers when he mentioned “the great replacement, with the Islamization of France, mass immigration and constant insecurity.”

The so-called great replacement, a contentious theory that claims the West’s population is being replaced by immigrants, has been cited by white supremacists in mass shootings in Christchurch, New Zealand, and El Paso, Tex.

But Sophie Michel, a former history teacher and a mother of nine, said she believed the theory, pointing to the growing number of immigrant families living in her apartment building in western Paris.

“We’re the last white people there,” she said, “this is for real.”

The name of Mr. Zemmour’s new party, “Reconquest,” evokes the centuries-long period known as the Reconquista, when Christian forces drove Muslim rulers from the Iberian Peninsula.

Two of Ms. Michel’s children also attended the rally, along with hundreds of young people. Hortense Bergerault, 17, said she followed Mr. Zemmour on Instagram, where he has nearly 150,000 followers, ranking only behind Mr. Macron and Ms. Le Pen among the presidential candidates. “I have many friends who are really into it,” she said.

Mr. Martigny, the political scientist, said that Mr. Zemmour was the product of “culture wars” that had gradually spread far-right ideas across society, especially through Fox-style news networks, clearing “a space for a Trumpian player in the French political life.”

“They have understood that there is no lasting political victory without a prior cultural victory,” Mr. Martigny said of Mr. Zemmour’s team.

This cultural win was evident in Villepinte, where many supporters referred to Mr. Zemmour’s books and TV appearances as eye-opening experiences. Some wore baseball caps reading “Ben voyons!” — a rejoinder that Mr. Zemmour often uses to dismiss criticism, and which roughly translates to “Oh, come on!” The crowd even chanted the phrase when Mr. Zemmour, speaking from his lectern, mocked those accusing him of being a fascist.

Antoine Diers, a spokesman for Mr. Zemmour’s campaign, said that although France and the United States were two different countries, they had “obviously” looked at Mr. Trump’s 2016 presidential run “because it was a success.”

Raphaël Llorca, a French communication expert and member of the Fondation Jean-Jaurès research institute, said Mr. Zemmour had successfully waged a “battle of the cool” designed to popularize his extreme ideas and “reduce the cost of adherence” to the far right.

His YouTube campaign-launching video, riddled with cultural references, has drawn nearly 3 million viewers — evidence of his command of pop culture codes, Mr. Llorca said.

“The cool is a way to defuse and neutralize otherwise extremely violent” ideas, he added.

In October, Mr. Zemmour said his success would depend on his ability to appeal to both the conservative, bourgeois electorate and that of the Yellow Vests, the mostly working-class movement that protested against economic injustice that Ms. Le Pen has long courted.

Whether he can achieve that balancing act is far from clear, as shown by the attendance at the rally. The main economic proposal he outlined last weekend — slashing business taxes — is unlikely to speak to working-class voters.

Mr. Zemmour’s theatrical entrance into the convention center, to the sound of dramatic music, also did little to eclipse the fact that he has so far failed to garner support from any major political figure, or party. This remains a major difference from Mr. Trump, who could count on the powerful Republican Party and solid financial backing.

Mr. Zemmour said he was the target of the media and the elites. He praised the crowd before him for standing up to these attacks. “The political phenomenon of these rallies, it’s not me, it’s you!” he shouted.

But some of his supporters might also prove to be his greatest liability.

Midway through his speech, dozens of sturdy militants threw punches at several activists from SOS Racisme, an antiracism organization, who had stood on chairs at the rally and revealed T-shirts spelling out the phrase “NO TO RACISM.”

Prosecutors have opened investigations into the violence, including one against a man who lunged at and grabbed Mr. Zemmour as he walked toward the stage.

Mr. Diers, the spokesman, said the antiracism activists had acted provocatively and that he had called on supporters “not to use force unreasonably.”

Mr. Llorca, the communications expert, said that with such a polarizing campaign, Mr. Zemmour risked “being overwhelmed” by the extremism of his own supporters.

The French news media later reported that some of those who had attacked the antiracism activists were neo-Nazi militants. As they chased down the activists toward the entrance hall, wearing black mufflers that hid their faces, they were stopped by a security staff member.

“Thank you for being there,” he told them. “You did the job!”