Philadelphia’s Home Rule Charter, adopted in the 1950s as reform-minded Democrats were taking control of City Hall, is filled with policies aimed at ending the corruption of the Republican machine that had ruled local politics since the 1800s.

City leaders now say that one of those policies known as the “rule of two” — to prevent political patronage in hiring and promotions, it requires managers to choose between the two candidates with the highest exam scores — has had the unintended consequence of limiting diversity in the municipal workforce, especially by preventing nonwhite city employees from getting promotions.

Voters on Nov. 2 will decide whether to eliminate the rule thanks to a proposed amendment to the charter championed by City Council Majority Leader Cherelle Parker.

“When we move up the ladder, those diversity numbers tank,” Parker said in an interview. “What barriers to entry can we remove to make it feasible for the City of Philadelphia to not only diversify its workforce, but to provide access to applicants to move up the ladder?”

Parker and other Council members have for years hounded successive mayoral administrations about the lack of diversity in the city’s bureaucracy, noting that while diversity among new hires has improved over time, the pool of people who win promotions is more white and more male than the city’s population. City department heads and human resources officials often point to the rule as a reason they can’t do more to make the city workforce more reflective of the city’s people.

“It’s been proven through many studies that there is discrimination in standardized testing,” Parker said. “Now we can say, ‘Wait a minute — we’re giving you a tool to work with to diversify your workforce.’ ”

Just over 80% of the city’s 26,800 executive branch employees are in the Civil Service System. The rest are senior-level positions hired directly by top administration officials known as “exempt” employees.

A 2015 analysis by The Inquirer found that, among city employees who earned more than $70,000 per year, 64% were white, and 72% were male. But among those who made less than $35,000, 67% were Black, and 55% are male.

Overall, Philadelphia’s population is 38.3% Black, 34.3% white, 14.9% Latino, and 8.3% Asian, according to last year’s Census.

Patrick Christmas, policy director for Philadelphia’s good government group the Committee of Seventy, said he isn’t concerned that eliminating the “rule of two” will mean a return to political favoritism for all city jobs, noting that the rest of the Civil Service system will stay in place and that a change is needed for city government to be nimble and responsive in a 21st century environment.

“This rule was needed for a long time, but it’s not anymore, both for diversity reasons and for effectiveness,” Christmas said.

A 2018 report by the Pew Charitable Trust found that Philly’s “rule of two” was the most restrictive hiring policy of its kind among the 30 largest U.S. cities.

Mayor Jim Kenney’s administration testified in support of the legislation that put the question before voters.

Michael Zaccagni, the city’s interim director of human resources, said the charter amendment will make the city more efficient by allowing managers to decide whether harder-to-quantify traits such as past experience ought to weigh as heavily as exam scores.

“Testing doesn’t have this level of accuracy that everybody gives it” credit for, Zaccagni said in an interview. “We’re going to be able to reach more candidates who are qualified for the position.”

Currently, managers must choose between the two candidates ranked highest on what are known as “eligible lists” for job openings. The rankings are based on written and oral exams that are tailored to the open positions.

If the charter amendment is adopted, the city personnel director will determine how many applicants make it to the final round for each opening.

Although political patronage has largely disappeared from the bulk of the city workforce that is covered by Civil Service, it is far from a thing of the past in Philadelphia. The offices of independent elected officials and agencies like the Harrisburg-controlled Philadelphia Parking Authority, for instance, employ scores of people with ties to politicians and party ward leaders and committee people.

Among a total of four ballots questions this year, two more would also change the workings of city government.

In one, voters are asked to amend the Home Rule Charter to create a Department of Fleet Services, to oversees some 6,000 city vehicles and trucks.

The other asks if the city should amend the charter to impose a mandatory annual $25 million appropriation into the city’s housing trust fund. Kenney opposes this, saying it would wrongly limit the city’s ability to manage its money.

Finally, the last ballot question is a survey on marijuana legalization. It asks voters if the city should call upon the Pennsylvania General Assembly and Gov. Tom Wolf to decriminalize, regulate, and tax the use and sale to those at least 21 years of age of cannabis for recreational purposes.

Staff writer Julia Terruso contributed to this article.