The field for Democratic nominee for mayor of Pittsburgh got a little wider this weekend.

At a public library auditorium in Homewood Saturday, John Welch declared a “people’s campaign,” becoming incumbent Mayor Bill Peduto’s first declared opponent in the May 16 Democratic primary for the 2017 election.

Welch, the dean of students at the Pittsburgh Theological Seminary, focused the remarks that opened his campaign on unequal development across the city, gentrification and police brutality. With his issue-based approach barely mentioning Peduto, the Carnegie Mellon graduate is poised to play the role that former Democratic presidential candidate, Bernie Sanders, I-Vt., played in last year’s presidential primaries. Welch could — and should — bring to the forefront of the public’s attention issues like these that matter to Pittsburghers but remain outside the mayor’s agenda.

Pittsburgh’s police force has seen plenty of controversy and tragedy in the past decade. Welch mentioned the nationally reported 2009 killing of three officers and Jordan Miles’s alleged assault by police in his speech. The former city police chaplain proposed an approach to issues with the force focused on both these sides — officers and communities. Combining the interests of the two sides is central — officers should have a greater stake in the communities they protect. Focusing specifically on the interests of one of these sides or the other is only a recipe for failure.

This is particularly relevant in the immediate aftermath of former Police Chief Cameron McLay’s resignation last November following a vote of no confidence from members of the Fraternal Order of Police among the city’s force. The vote came in stark contrast to Peduto’s continued support for the chief and his policies and marks a concerning gap that might not bode well for the success of future police reforms.

A “people’s campaign” from Welch on issues surrounding the police force in Pittsburgh easily has the potential to shift Peduto’s approach, should he win a second term in office. But given Welch’s East End origins, the issue of gentrification could possess even greater urgency and potency for his campaign to shift the incumbent’s take on the issue to the left.

Gentrification and uneven urban expansion have affected neighborhoods across Pittsburgh, but areas in the city’s east have borne the brunt of unstructured, under-regulated development. The need for the city to improve in dealing with the issue was underscored by Welch’s comment at his campaign kick-off Saturday that “it’s not fair when East Liberty can look like Monaco, and Beltzhoover looks like Monaca, [Pennsylvania.]” The city must ensure that all groups have a say in development, particularly when changes directly affect their communities.

A challenge to an incumbent in a primary election is as unlikely in Pittsburgh as anywhere else. But even if Welch fails to win the Democratic nod this year, he can still offer a vital service to Pittsburghers. Besides simply offering an alternative, Welch’s background and platform bring a lot to bear on viewpoints not as frequently considered in Peduto’s approach to governing the city.

Whether he plays the Sanders to Peduto’s Hillary Clinton and drags the mayor left or sheds light on issues that should be on the city’s agenda, a challenger makes the race more interesting and more valuable to everyone involved.