When John Linder captured the mayor's seat in Chester in 2011, he stood among the city's unified Democratic council - the first in more than a century - and vowed to change a community burdened by problems.

Together, the five-member council planned to tackle Chester's climbing homicide rate, its failing schools, and the $5 million debt that qualified the Delaware County city as "financially distressed."

Then came the intra-party fighting.

Now, on the cusp of another mayoral election, Linder stands apart from the council. Its members are standing with Thaddeus Kirkland, a 12-term state representative from Delaware County.

On Tuesday, Linder and Kirkland will run as mayoral candidates in the primary, both vying for the votes of more than 15,000 registered Democrats in a city of 34,000.

The winner will face former Mayor Wendell Butler, a Republican, in November. Nearly 5,300 residents are registered Republicans.

Two incumbent council members and the controller are up for reelection. Each has aligned with Kirkland. Linder enlisted three newcomers to run for the council on a slate with him.

Both men are Chester natives, and both have pledged sweeping changes. But first, they said, a larger issue looms: Infighting has made governance nearly futile.

Chester, on the Delaware River, is one of the most violent and impoverished cities in the state. In 2014, its homicide rate hit 30. Three have been recorded this year, according to Pennsylvania state police.

One-third of residents live below the poverty line. In 2013, a state audit of the Chester Upland School District said students "may never recover from the loss of an effective education."

The candidates agree the election is bigger than a mayor's race: Unity is needed among the five-person council, which includes the mayor, to change Chester.

Linder said Chester's government structure - which gives all council members an equal vote - has rendered him ineffective. He is consistently outvoted, he said, and needs more time and new council members to pursue his ideas.

Kirkland said Linder's ideas were stymied because he "shunned" the council. If elected, Kirkland said, he would take a pay cut of nearly $50,000 in leaving the state legislature. The mayor's salary is $35,000.

"You can't be the Lone Ranger mayor," Kirkland said. "You have to build a relationship to move this city forward."

Four years ago, Linder won the mayoral primary with 85 percent of the vote. This election, he has lost the support of both city and county Democratic parties, which aligned with Kirkland.

Contested Democratic primaries such as this are rare in Delaware County, said David Landau, chairman of the county Democratic Committee. Even rarer, he said, is for an incumbent to lose support.

Among the most polarizing issues is Chester's police department - specifically Commissioner Joseph Bail. Kirkland has called for Bail's removal, saying he is "insensitive" to Chester's needs.

"Why should I get rid of him?" Linder said. "I asked him to take guns off the street, and he took 553 guns off the street. I asked him to give me a narcotics squad, and he gave me a narcotics squad."

If reelected, Linder said, his focus will be on confiscating more guns, installing surveillance cameras on streets, and creating a tax incentive-based program to bring more small businesses to Chester's struggling downtown.

"I've been in office for four years," Linder said. "Does [Kirkland] have the experience and the track record to carry out what he says he will carry out?"

Kirkland said his focus will be on eliminating gangs and repairing the city's "hostile" relationship with PPL Park, the 18,500-seat stadium brought to Chester to boost its economy. He wants to build a marketing campaign for the city, too.

"It's hard to tell folks to come and bring your children to Chester," Kirkland said. "We have to put this city in a better light."