As one urban gardener after another beseeched Cherelle Parker to prevent the green spaces that they had spent years nurturing from being gobbled up by developers, she furiously took notes in her trademark spiral notebook and barely said a word.

Eventually, Ms. Parker, the Democratic nominee for mayor, did address the neighborhood groups that had gathered on a chilly afternoon at Las Parcelas garden in north central Philadelphia. Yes, she would convene as many stakeholders as possible to come up with a solution. But a savior she was not.

“I’m not Superwoman — I can’t fix everything up by myself,” she said as nearby construction clanged in the background. “I want to manage expectations.”

Ms. Parker was talking about Philadelphia’s 450 community gardens, but she might as well have been referring to her 142-square-mile hometown.

On Tuesday, Ms. Parker, a 51-year-old former state representative and City Council member, is favored to be elected mayor of Philadelphia and to be the first woman to lead the city and its 1.6 million residents.

Should she win, she would have four years — or more likely eight, given that each of the last five mayors, all Democrats, won two terms — to grapple with the challenges bedeviling the nation’s poorest big city, headlined by gun violence, opioid overdoses and crumbling and chronically underfunded public schools.

As a Black woman who was the daughter of a teenage mother and is now the mother of a Black son, Ms. Parker has said that she can relate to the everyday struggles faced by many of her neighbors.

She has pledged to hire hundreds more police officers and bring back what she called “constitutional” stop-and-frisk, and she has been open in asking for help from the National Guard to tackle the open-air drug market that has made shootings common in the Kensington neighborhood.

But with two-thirds of Philadelphians saying that the city is on the wrong track, what many residents say they want from their next leader, as much as any policy blueprint to navigate the city’s ills, is optimism and energy.

Symbolism, after all, has always suffused a city whose history as a cornerstone of American democracy is so central to its identity. And Ms. Parker, as Philadelphia’s 100th mayor, would be the face of the city in 2026, when the country celebrates the 250th anniversary of the Declaration of Independence.

“She’s very charming, she’s very charismatic — a calming presence,” said Cait Allen, president of the Queen Village Neighbors Association, which represents a historic and affluent area not far from Independence Hall. Citing Ms. Parker’s winning pitch in the intensely fought Democratic primary to make Philadelphia the “safest, cleanest, greenest city” in the country, Ms. Allen, 37, said, “She was the candidate who seemed to prioritize reality over philosophy.”

Ms. Parker would succeed Mayor Jim Kenney, who is leaving office after two terms. Early in his tenure, Mr. Kenney shepherded in a soda tax to help fund pre-K education. More recently, the city’s finances have stabilized, and its bond rating has been upgraded.

But against the wearying backdrop of the pandemic, Mr. Kenney’s second term has been overshadowed by the civil unrest following the killing of George Floyd and by the proliferation of gun violence, such as a mass shooting in July that was exacerbated by a botched police response.

In an interview, Mr. Kenney, 65, said that “there’s a cultural shift that needs to be made.”

He added, “Not that I’m not progressive or that I’m not understanding of people of color’s struggles, but I’m still a white man.”

Ms. Parker is a former English teacher from northwest Philadelphia who has a strong working relationship with Gov. Josh Shapiro, a fellow Democrat. She will no doubt be integral to her party’s efforts to bolster turnout for President Biden, Senator Bob Casey and other Democrats in 2024, when Pennsylvania could affect the balance of power in the White House and Congress.

Asked in an interview which mayors she hoped to emulate, she mentioned three: Maynard Jackson of Atlanta, for his stressing of economic opportunities; Sharon Weston Broome of Baton Rouge, who told Ms. Parker not to abandon “chemistry for credentials”; and Eric Adams of New York, for prioritizing “emotional intelligence” among members of his staff.

“I do not like to see folks engaging in what I call ‘I know what’s best for you people’ policymaking,” she said. “Change is not supposed to happen to a community. Change happens in partnership with a community.”

Her Republican opponent, David Oh, a former colleague on the City Council, would also make history if he pulled off an upset, becoming the city’s first Asian American mayor.

A lifelong Philadelphian like Ms. Parker, Mr. Oh, 63, a former prosecutor, has mounted a spirited and unorthodox campaign, aimed at wooing immigrants, to overcome the daunting math in which registered Democrats vastly outnumber Republicans.

In an interview outside City Hall, after a flag-raising ceremony commemorating the 100th anniversary of Turkey as a republic, Mr. Oh noted his embracing of some positions to the left of Ms. Parker, such as limiting the use of stop-and-frisk. And unlike Ms. Parker, who counts the powerful building trade unions as a strong supporter, Mr. Oh opposes a proposed new basketball arena for the 76ers in downtown Philadelphia that local activists say would devastate Chinatown.

He was disappointed, though, that Ms. Parker had only agreed to one debate.

“It’s not about winning the election,” he said. “It’s about communicating to the voters. We must engage them in order to lift their spirits and put them behind a vision and a solution.”

At a stylish coffee shop in a gentrifying part of West Kensington, Al Boyer, 24, and Alex Pepper, 38, both baristas, cited the opioid crisis and gun violence as top priorities for the next mayor.

One man with a needle hanging out of his neck had recently died from an overdose across the street from the coffee shop. Just a few blocks away, groups of homeless people lay sleeping under blankets on the sidewalk along Kensington Avenue.

Mr. Pepper said he supports establishing drug consumption sites supervised by medical and social workers — something Ms. Parker opposes. Still, Mr. Pepper said he would vote for her.

“The lesser of two evils,” he said.

Joel Wolfram contributed reporting.