Is Flint the poster child of US environmental racism?
Flint residents hold bottles full of contaminated water during a news conference after attending a House Oversight and Government Reform Committee hearing --AFP

Would the scandal surrounding the lead-contaminated water in Flint, Michigan happen if the residents were rich white people?

Democrats Hillary Clinton and Bernie Sanders raised this sensitive question Sunday as they highlighted the health disaster blamed on penny-pinching political decisions in this city that once relied heavily on the auto industry.

The political rivals found common cause in their criticism of Michigan's Republican Governor Rick Snyder, calling for him to resign.

Both candidates agree that Flint's neglected water distribution network, eaten away by corrosion, needs an overhaul.

They called for more action from the federal government, and accountability overall.

"What I heard and what I saw literally shattered me, and it is beyond belief that children in Flint, Michigan, in the United States of America in the year 2016 are being poisoned," Sanders said at a CNN debate.

He called for rebuilding America's "crumbling infrastructure," water systems, wastewater plants, roads and bridges.

Clinton said the state should "immediately" send money to help Flint.

Both have called for revamping Flint's water supply network, eaten away by corrosion, and condemned Snyder's cost-cutting measures that led to more than 8,000 children ingesting lead each day.

But the two presidential contenders are also targeting their strongest messages at Flint's black community and, beyond, at African Americans suffering economic and social injustices elsewhere in the United States.

Some are calling the Flint scandal an example of environmental racism.

The expression has been used in recent decades to describe how African Americans are disproportionately exposed to pollutants in air, water and the ground.

- Legacy of segregation -

Segregation may have been abolished nationwide in 1964, a century after the Emancipation Proclamation, but African Americans still have lower wages and poorer housing conditions than whites on average.

"African American communities across the nation have always been disproportionately representative of the toxic areas," said Laura MacIntyre of the University of Michigan-Flint.

"Most of the people that bear the brunt of living in the polluted areas or next to incinerators or factories or all sorts of places that have toxic or hazards as waste are communities of color and Flint is no exception.

"It is a racial issue in terms of the fact that we have to deal with it disproportionately."

Those inequalities were similarly illustrated in the aftermath of the devastation Hurricane Katrina brought on New Orleans in 2005.

After losing about half its population and nearly all of its auto industry, Flint now has about 100,000 inhabitants -- 57 percent of them African Americans, and nearly half of residents in poverty.

A recent study found that the percentage of children with elevated levels of lead in their blood increased "particularly in socioeconomically disadvantaged neighborhoods."

It noted that aging infrastructure was to blame for more children being exposed to lead through tap water.

Flint has the highest home vacancy rates in the United States -- with 7.5 percent of homes empty -- according to a RealtyTrac report.

That's nearly five times higher than the 1.6 percent national average.

The situation is even worse in Flint's northern, primarily African American, neighborhoods. Some streets are completely deserted, with house after house boarded up or dilapidated.

- 'Flint Lives Matter' -

"We lost a lot of schools, I can't tell you how many schools, and you see how the water situation was ignored... This wouldn't have happened in a white neighborhood," said Charles Marion, a father of three.

That's a theme Clinton, who has a strong African American voter base, has repeated recently.

"If the same thing that's happening in Flint had happened in Grosse Pointe or Bloomfield Hills, I think we all know that we would've had a solution yesterday," she said, referring to wealthy suburbs of Detroit.

Civil rights activists are taking up the cause as well.

While the Oscars ceremony took place a week ago amid controversy over the lack of diversity in Hollywood, Flint was organizing a Blackout for Human Rights concert, with a "Justice for Flint" theme and Stevie Wonder as surprise guest star.