As the mayor of Jackson, Chokwe Antar Lumumba represents Mississippi's largest city of Democratic primary voters.

In February, he endorsed Bernie Sanders for the party's nomination, securing a coveted endorsement from a progressive rising star and underscoring the Vermont senator's decades of organising history in communities where other presidential candidates have rarely stepped foot.

Days later, Joe Biden's resurgent campaign won crucial victories in the party's race for the nomination, with older black voters carrying Biden's win in several states.

When the then-34-year-old Lumumba was elected in 2017, he promised to make Jackson "the most radical city on the planet." His father, Chokwe Lumumba Sr, who served as mayor before his death in 2014, arrived in Mississippi from Detroit in the 1970s and launched a career in black activism.

His son's overwhelming election in 2017 — receiving 94 per cent of the vote — didn't reflect the rising tide against the legacy of white supremacy in the state but the fruits of radical black organising in the south, which has long argued that the region is not a red-state stronghold but a seat of black power held hostage by conservative legislatures enshrined through gerrymandering and systemic racism.

As a rising progressive Democrat in the Deep South, he was courted by Joe Biden, Michael Bloomberg and Pete Buttigieg for his endorsement.

First, Lumumba and several other mayors representing majority-black cities in the South — Steve Benjamin of Columbia, South Carolina, LaToya Cantrell of New Orleans and Randall Woodfin of Birmingham, Alabama — asked for the campaigns to consider "a kind of human rights and development agenda that is essential for our cities to meet the needs of residents and move our economies forward."

Combined, their cities represent nearly 2 million people, including 345,000 Democratic voters, and 196 Democratic delegates.

"And because our states' presidential primaries occur in the first few months of the presidential primary season, we fully intend to make the challenges our cities face and the priorities of our Southern communities front of mind for your campaigns," the mayors wrote in a letter to the campaigns.

The mayors urged for policies that address poor air quality and environmental concerns in a region where the poorest are the most vulnerable to the climate crisis and refinery pollution, and where cuts to federal housing and food programmes have threatened housing stability and overburdened community food pantries.

Their letter called for public transit and infrastructure investments, a higher federal minimum wage, bolstering federal safety nets, health policies that support black mothers and indigenous families, and other commitments to economic, social and racial justice.

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Mississippi is often ranked as the least-healthiest state in the US, from the stark numbers of children in poverty to the rates of low birth weights.

"When people asked me how I felt the morning after Donald Trump was elected, I told them, 'I woke up in Mississippi,'" Lumumba tells The Independent. "When we're told the country is experiencing success economically, or we're told that we're dealing with the recession — we don't feel it in Mississippi. We're always at the bottom. We're at the bottom when it comes to wealth, education and health, and none of those things are coincidental."

The state's poor health outcomes also underline his support for a Medicare for All, Sanders' signature policy plan to guarantee equal access to healthcare for all Americans through a nationalised platform.

"If the right to vote was the struggle of the 20th century, the right to healthcare must be the struggle for the 21st century," Lumumba says. "We look at it like it's some outlandish goal when nations all around us are doing it. ... The value of a human life should not be attached to your net worth."

Jackson also is a college town, with thousands of people living in and around the city while attending, working for or serving students from the region's seven universities. Sanders' proposal to eliminate college debt begins to repair "a dynamic where we're telling our children they can be anything they want to be yet we're attaching this financial burden to them," Lumumba says.

He also challenged the campaigns to address the country's crumbling roads and infrastructure against the rising tide of climate threats and lack of sustainable development.

"That requires investments in cities," he says. "If we're building more tanks — to protect what? To protect the nation that doesn't have the basic needs it requires?"

The mayor also relied on the results of a "people's caucus" that petitioned and challenged representatives of four candidates on issues of criminal and economic justice, healthcare and education.

Mississippi Votes director Arekia Bennett organised the caucus as part of the Movement for Black Lives, which tasked its membership to host unofficial voting caucuses in their respective cities.

The Mississippi caucus included 139 people from across the state.

Sanders overwhelmingly won the first and second rounds.

From that process, "the Sanders campaign demonstrated consistency not only in the policies that addressed the concerns people in Jackson had, but it demonstrated consistency with the respect of a candidate who we've seen a history of his commitment to those issues," Lumumba says.

The day after the results, Lumumba announced his endorsement.

Lumumba also has a history alongside the senator, who stood on the picket line with striking Nissan workers in the state as they fought to unionise, and joined an economic justice forum hosted by the mayor on the 50th anniversary of the killing of Martin Luther King Jr.

"He stood with us then as we look at the larger issue of economic justice and how economic justice plays a role in so many ancillary problems in our society, and how it contributes to other large problems like racism," Lumumba says.

Mayor Benjamin ultimately endorsed Michael Bloomberg, who's no longer in the race. Mayor Woodfin supports Joe Biden. Mayor Cantrell has not yet announced her endorsement.

Lumumba quotes Martin Luther King Jr's 1961 remarks: "Call it democracy, or call it democratic socialism, but there must be a better distribution of wealth within this country for all God's children."

"That's right on point," Lumumba says. "This idea of being radical, speaking up for what you see — I'm not interested in pageantry, I'm not interested in a coronation and doing the same old thing. Because the same old thing has been a failed practice and a failed policy for my people."

While the senator's campaign has pointed to support from an unprecedented working class coalition of people of colour, it's one that hasn't been carried by older black voters, who represent a significant number of Democratic voters and helped thrust Biden to a decisive victory in South Carolina, the electoral litmus test for the power of "the black vote."

Ahead of the battleground primary in Michigan on the same day as Mississippi's election, Sanders cancelled an event in Jackson to focus on the Midwest.

Analysts have pointed to a relative conservatism among older black voters, who have largely been risk-averse, particularly when faced to choose between white candidates, after generations have literally fought for their vote without any explicit promise their interests are represented once in office. Fearing the existential threat of a second Trump term, those voters perceive a "safe bet" in a less-polarising Democratic figure in former president Barack Obama's running mate.

"I believe that our community — and I don't want to speak in monolithic terms — but a portion of people who reside in black communities across the nation want to select a candidate that they feel has viability and is in position to advance past their concerns," Lumumba says. "What we see is a consensus, and some of it media-related, around one candidate that they believe is in the best position to do that. I think that's dangerous."

He says that shallow election analysis has failed to address policy, leaving a majority of voters in the dark as institutional Democrats converge around Obama's vice president.