The poisoned water crisis in Flint, Michigan, is set to become a central focus in the 2016 presidential election, at least on the Democratic side, as the candidates prepare to debate there next month.

Early this week Hillary Clinton’s campaign touted several new endorsements from three black religious leaders in Flint. Later the campaign published a short video encouraging donations to help bring clean water to the children of Flint. Clinton’s moves come as she competes with Vermont Sen. Bernie Sanders for the African-American vote in the South Carolina primary and beyond.

Last week, CNN announced a seventh democratic debate to take place in Flint between Clinton and Sanders on March 6, two days before the Michigan and Mississippi primaries. "Our Democratic candidates have run spirited campaigns focused on how to best move our country forward, and our upcoming debate in Flint, Michigan, is a critical setting to highlight what's at stake in these elections," DNC Chair Rep. Debbie Wasserman Schultz told CNN. "This debate is an opportunity to elevate the very serious issues facing the residents of Flint, and it's also an opportunity to remind voters what Democratic leadership can do for the economy — so that everyone in America has a fair shot."

A water contamination crisis started in Flint in April of 2014 when, in an attempt to save money, the city changed its water source from Lake Huron and the Detroit River to the Flint River. The corrosive Flint River water caused lead from old pipes to leach into the water supply, ultimately exposing 8,000 children to the poisonous element “that will have lifelong effects on their brain and nervous systems,” according to Vox on Monday. After the republican governor of Michigan, Rick Snyder, declared the city in a state of emergency last month President Obama declared it a federal emergency.

In its evaluation of the crisis, Politifact argued this week that the state’s governor bears a significant share of the blame but that Clinton and Sanders’ claims focusing on Synder have oversimplified the issue and given “a partisan spin to what is more fairly characterized as a broad failure of governance at all levels.”

Three African-American religious leaders from Flint endorsed Clinton on Sunday because she was the only candidate to step away from the New Hampshire primary last week to visit their mostly African-American city, according to Politico. “Secretary Clinton has certainly aided us in bringing added political attention to our plight in the city of Flint,” Rev. Hubert Miller said in a statement released by the campaign, “causing other politicians to move legislation on this subject and vowing to do everything within her power to assist Flint in recovering from this sinful social experiment we call the Flint Water Crisis.”

“Her voice was more than that of a politician,” Rev. Al Harris added, “it was the voice of a humanitarian.” For his part, Sanders has repeatedly called for the resignation of Snyder.

On Monday, the Clinton campaign released a short video promoting fundraising efforts for the people of Flint. The video spends most of its 60 seconds on Flint residents speaking about how they were affected by the water crisis, and at the end Clinton is heard saying, "This is the most important work we are ever called to do: to reach out, in every way we can, to lend that helping hand for every single person in Flint."

Republican candidates are set to debate in Michigan next month as well, though in Detroit on the third, according to Fox News. Flint has risen in the Republican debates only once, in Iowa when Ohio Gov. John Kasich said he didn’t know all the details of what Snyder had done. Overall, very little has been said by Republican presidential candidates on the water crisis in Flint, according to the Wall Street Journal. Front runner Donald Trump said last month that it’s “a shame what’s happening in Flint, Michigan. A thing like that shouldn’t happen. But again, I don’t want to comment on that.”