In 2014, Democrat Marty Walsh was sworn in as the 54th mayor of Boston, declaring his vision for a city with equal opportunity and “creative solutions to the challenges of the 21st century,” according to his website. Three years later, Walsh’s incumbency is being challenged by another Democrat passionate about progress and equality: Boston City Councilor Tito Jackson.

At first, it is not obvious why Jackson would run against another liberal Democrat with whom he agrees on most issues. However, Jackson has made it clear that his plan is to challenge Walsh from the left, and that such a challenge is important not only for the city of Boston, but also for the Democratic Party in general.

At a recent panel hosted by the Tufts Democrats on immigration law, Jackson made his feelings about the needs of the party perfectly clear.

“This last election tells us something as Democrats,” Jackson said during the panel. “No more playing the middle. No more playing moderates.”

Indeed, contentions between the progressive and moderate wings of the party have become increasingly common within the Democratic Party not just in Boston, but on a national level.

This effect was most clearly seen in the 2016 Democratic Presidential primaries. The heated race between former Secretary of State Hillary Clinton and Senator Bernie Sanders had those “with her” and those “feeling the Bern” at each other’s throats for much of the past twelve months.

Most of the conflict between Sanders and Clinton came down to a division between the left and center. “Sanders basically has faith that there is a majority view in this country that supports much more aggressively redistributive policies…and a much more ambitious government effort to set a high minimum standard of living (single payer, a higher minimum wage) than Clinton can accept,” Greg Sargent noted in the Washington Post. Clinton has also been cited as being significantly more conservative on defense and international issues.

However, many of her other positions on issues, such as individual rights, are just as liberal as Sanders’. Some of her stances have also shifted throughout time, particularly as she adopted many of Sanders’ ideals into her platform after his defeat. Still, a portion of the party remained reluctant to get behind her, in some cases never changing tune.

And just as many gravitated towards Sanders for his more drastically liberal policies on matters like health care and affordable education, Jackson has also attracted attention for his agenda of committed activism. As with Sanders, this has resonated particularly with young people.

But is this disparity reflected between Jackson and Walsh? Some think not. Political Science Professor Jeff Berry, for one, doesn’t see the real motivation for Jackson to run.

“Both [candidates] are very progressive,” he said. “Walsh is quite liberal, so it doesn’t reflect any—or much—of a schism.” He adds, however, that there is “some dissatisfaction that the party is not energetic enough and not doing enough for income inequality.”

Income inequality, as well as inequality in housing and education, is one of the main pillars of Jackson’s platform.  A Boston Globe article by Adrian Walker announcing Jackson’s candidacy cited some of his focuses as “the social cost of underfunded schools, gentrification, and income inequality…He is running to be the mayor of those who feel left behind, even as much of the city is booming.”

One group that Jackson plans to champion is the city’s population of undocumented immigrants. Jackson has been very vocal about his investment in immigrant communities through his support of the TRUST Act and the maintenance of Boston as a sanctuary city, an issue Walsh has shown similar dedication to, though, perhaps, not with the same kind of fervor.

Jackson claims that one of the most important elements of this issue is that we “watch our language” and work to welcome immigrants into our community without branding them with dehumanizing labels like “illegal.”

At the immigration panel, he became particularly animated when speaking about this, smacking his palm down on the table as he spoke, and declaring, “It’s actually time to stand up and say, ‘We love poor people!’, ‘We love immigrants!’”

Jackson’s charisma is one element that certainly distinguishes him as a candidate. Jackson is spirited, witty, and upbeat, especially when it comes to encouraging legislative action and community activism. But he is also strikingly realistic.

“My message to all of you is that the cavalry is not coming,” he told students in the panel audience. “Nobody is coming to save us.” He then challenged students to take on active roles as leaders and activists both on and off campus.

“The last thing I will say is from the 21st century poet Lil Jon’s ‘Turn Down for What,’—it is absolutely critical that you literally ‘step it up,’” he joked.

Jackson’s energetic position on issues like sanctuary measures may be the key to an edge over Walsh. He is particularly in tune with young, diverse audiences, and his commitment to unapologetic equality may resonate especially deeply on campuses like Tufts, where issues like the possibility of becoming a sanctuary campus is on the minds of many.

“Young voters might be more supportive of Jackson…they are more diverse,” said Berry.

Even so, students have not expressed overwhelming dissatisfaction with Walsh.

“Mayor Walsh has done an excellent job encouraging voter registration and engaging students in government,” Tufts Democrats President and senior Ben Kaplan said. “Both Mayor Walsh and Councilor Jackson recognize that college students are an important part of the community, which is great to see.”

However, some do see the potential for Jackson to improve upon Walsh’s leadership. Junior Alex Mitchell, for one, critiqued the way Walsh handled the city’s bid for the Olympics, marijuana legislation, Boston’s public schools’ budgets, and the Boston Police Department body camera effort. He, too, thinks that Jackson’s emphasis on advocacy is his best shot against Walsh.

“Jackson’s local ties and history of advocacy is going to help him, plus, District 7, which he currently represents, is critical in mayoral elections. However, Walsh has really been capitalizing on the Trump administration’s decisions over the past week or two, which puts him in a good position” he said.

While the policy differences between Walsh and Jackson may not be as stark as in the 2016 primary, there are certainly still some parallels between this race and that contest. The most conspicuous similarity is that Jackson enters the race as a sizable underdog.

According to Berry, Walsh has a significant fundraising advantage, like Clinton’s, that will almost certainly enable him to get the vote out more effectively.

“I’m not sure exactly what [Jackson’s] path to victory would be,” Berry said.

Of course, while Sanders was not able to win last spring, he did provide a significantly larger challenge to Clinton than their initial tallies of cash on hand would have suggested. According to Robert Borosage, the co-director of the progressive Campaign for America’s Future, Sanders’ success was primarily the result of “this younger generation coming into politics and moving with their own energy.” If Jackson is able to harness young voters to a similar degree as Sanders, in a student-dominated city like Boston, he might be able to succeed.

Jackson has recognized this fact. Speaking at the immigration panel, he said, “Every social movement in our country’s history was vastly moved by young people. Don’t wait your turn. They want you to wait your turn.”

He has from now until November to try and create such a movement behind his candidacy. In the meantime, he has at least created interest among observers of Massachusetts politics in what could have been an essentially uncontested race.

“Both Mayor Walsh and Councilor Jackson are devoted public servants and have compelling messages,” Kaplan said. “I am excited to see how the race plays out.”