That may be about to change. Last week, Sanders offered up an environmental-justice amendment in the Senate in response to legislation that would effectively block President Obama's effort to curb greenhouse-gas emissions from power plants, a key pillar of the White House climate agenda.
The amendment calls on Congress to affirm a wide array of statistics pointing to the heightened public health risks faced by African-Americans, Hispanics, and American Indians and Alaska natives as a result of air pollution.
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Sanders's amendment also pushes for the creation of "a national environmental and climate justice climate change plan" intended to address "the disproportionate impacts of air pollution to low-income and minority communities."
Environmental justice is not officially listed as a national demand of the Black Lives Matter movement, but the fight for environmental justice and the modern-day civil-rights protest movement are built on the common premise that communities of color have been disproportionately impacted by years of national policy rooted in systemic racism.
For now, Sanders's amendment is not attached to any legislation. But the senator's push for environmental justice is likely to resurface as the Capitol Hill fight over the president's climate agenda heats up after Congress returns from August recess. And some environmentalists predict that Sanders will become increasingly outspoken on environmental justice in the coming months.
"Scientific evidence shows communities of color suffer more from the negative effects of inhaling polluted air and drinking polluted water," Mike Casca, an aide to Sen. Sanders, told National Journal. "The neighborhoods where these Americans live will continue to be the hardest hit if we don't act to stop climate change now."
Without question, environmentalists love Bernie Sanders. The senator rails against Republicans who question the science of climate change, and he has made opposition to the Keystone XL pipeline a key issue on the campaign trail.
Sanders has won widespread praise from green groups. And earlier this month, progressive environmental group Friends of the Earth Action endorsed his 2016 bid, marking the first official nod from any major environmental organization of the presidential race.
But some activists say that while Sanders's stand on environmental justice is a step in the right direction, the Vermont senator must do more to elevate the issue and spell out a way to solve it.
"This is very encouraging, but I would give him a solid 'C' on environmental justice overall," said Anthony Rogers-Wright, the policy director for the nonprofit Environmental Action. Rogers-Wright added that while the senator's environmental platform stands to benefit low-income and minority communities, Sanders has not always articulated the intersection between racial justice and environmental protection.