By Tuesday night, Philadelphia Democrats will have chosen their candidate to be the city’s next mayor. A crowded field and concerns over crime are testing liberals’ ability to break out beyond more establishment figures. 

For weeks, the field has been split into a top tier and a slightly lower tier, with three women virtually tied at about 20 percentage points of support and two men hovering in the mid-teens. 

Following the election of a liberal county commissioner, Brandon Johnson, as mayor of Chicago, liberal activists and teachers unions are energized and turning their attention to Philly, where they are hoping for another big win for the left-wing flank of the Democratic Party. 

The winner of Tuesday’s primary is nearly guaranteed to become the next Philadelphia mayor come November. The heavily Democratic city has not elected a GOP executive since President Truman was in the Oval Office.

One former city council member, Helen Gym, is the chosen candidate for the left. A long-time teacher, charter school founder, and civil rights activist, Ms. Gym has rallied with Senator Sanders and Congresswoman Alexandria Ocasio-Cortez. She also has the support of Mr. Johnson as well as Boston’s liberal mayor, Michelle Wu. Aiming to seize on citizens’ fatigue for typical, big-city politics, Ms. Gym has remained steady at between 15 and 20 points in the polls since joining the field.

When asked at a debate how she would solve Philadelphia’s skyrocketing crime rates, Ms. Gym proposed hiring more detectives to solve violent crimes. She also called for “non-police” mental health task forces to intervene with people having mental episodes instead of deploying cops in such cases. 

While serving on the city council, Ms. Gym argued that youth violence could be solved by investing in libraries and advocated for decriminalizing traffic violations. 

A former Pennsylvania governor and Philadelphia mayor, Ed Rendell, has said that Ms. Gym’s candidacy is a real test for the left flank of his party. “If Helen wins, that’s a big story, because it means the progressive movement won,” Mr. Rendell told the New York Times. He is supporting another candidate. 

Ms. Gym’s closest competition — a former city council member, Cherelle Parker, and a former city controller, Rebecca Rynhart — have also stayed steady around 20 points. Ms. Parker, who received the endorsement of the incumbent mayor, Jim Kenney, has promised to address the city’s surging violent crime rates by hiring more police officers. Her ties to organized labor and role as a ward boss in northern Philly allowed her to start off the race with high name recognition, a string of endorsements, and organizing on the ground. 

Ms. Rynhart, who has received the endorsement of three retired mayors, including Mr. Rendell, and the editorial board of the Philadelphia Inquirer, has promised to make the city “safer, cleaner, and more equitable for everyone.” 

Running as a transparency-focused candidate, Ms. Rynhart won plaudits for auditing the city council, the mayor’s office, and Philadelphia’s police department, which uncovered a number of inefficiencies with regard to personnel, police conduct, and financial waste.

The two men who hover slightly below their competitors — a former city council member, Alan Domb, and a supermarket magnate, Jeff Brown — have poured millions of dollars of their own money into their respective campaigns. 

Mr. Brown is the most conservative candidate in the race, racking up endorsements from the unions that represent municipal employees, transportation laborers, and employees of the food industry. He has made concerns about crime the centerpiece of his campaign.  

At a recent debate, Mr. Brown called out the former city council members who are running for mayor, all of whom voted for a reduced police budget in the wake of the George Floyd protests in 2020. “The first thing I wouldn’t have done is defund the police like all of the council people on this stage tonight,” he said.

Those who advocate for reduced police budgets have “let the ranks dwindle” to the point that there is “no visible police presence on the streets,” he said. According to one Fox poll, 64 percent of Philadelphia residents have heard gunshots in their neighborhood in the last year. 

Between January and March, Mr. Brown saw his support among Black Philadelphians — those most affected by crime — increase to 36 percent from 26 percent. 

The Republican Party already has its de facto candidate — another former city council member, David Oh. Running in an uncontested primary, Mr. Oh is hoping to be the first GOP mayor of Philadelphia in more than 70 years. 

Mr. Oh told the Sun’s Dean Karayanis that his party has given up on a troubled city that is desperate for change. “Nationally, Republicans have been looking at the knockout blow — win the presidency, the Senate — and I think what they’ve failed to do is understand the importance of the jab,” Mr. Oh said.  The GOP has attempted to “draw an imaginary border between ourselves and Philadelphia, the most populated county in our state,” to its own detriment.

The dynamics of the races in Chicago and Philadelphia are strikingly similar: high crime rates, beleaguered residents, and teachers and police unions choosing their benefactors. Mr. Johnston was sworn in as the Windy City’s mayor on Monday thanks, in part, to his relationship with his city’s powerful teachers union. 

Ms. Gym is running the same kind of insurgent campaign that Mr. Johnson ran in Chicago, relying on young peoples’ frustrations about the cost of housing and police misconduct. Also like her Chicago counterpart, Ms. Gym has received large campaign contributions from local and national teachers unions. 

The Philadelphia Federation of Teachers was quick to endorse her shortly after her campaign announcement. One former mayor, Michael Nutter, who has endorsed Ms. Rynhart, confronted Ms. Gym during a candidate forum in March over her stance on charter schools. 

While a private citizen, Ms. Gym, who is Asian, founded a charter school in Philadelphia’s Chinatown. Once she was elected to the city council, though, she opposed the establishment of all new charter schools, many of which would have been built in Black neighborhoods. 

A number of other candidates are running, including one state representative, a municipal judge, and a local pastor, but they have failed to garner more than 10 percent in any poll.