The political arm of leading environmentalist advocacy group League of Conservation Voters on Tuesday got behind congressional candidate Joe Neguse, one of three Democrats running in a primary for Colorado’s 2nd Congressional District seat being vacated by U.S. Rep. Jared Polis, who is running for governor.

Neguse, a former University of Colorado regent from the Democratic-leaning congressional district, said fighting climate change was one of the main reasons he got in the race, and the environmental organization said that’s a reason he won the endorsement.

“Joe Neguse will never stop fighting to protect our public lands and our right to clean air and water. He is part of the new generation leading the way to create a clean energy economy, prioritize racial justice and implement an equitable political process essential for our democracy,” said League of Conservation Voters Action Fund Senior Vice President of Government Affairs Tiernan Sittenfeld in a statement. “We need voices like Joe Neguse’s now more than ever and we are excited to endorse him in this historic campaign.”

If elected, Neguse, 33, would become the first African-American sent to Congress from Colorado and one of the youngest members of Congress. An attorney, Neguse stepped down earlier this year as executive director of Colorado’s Department of Regulatory Agencies, and he lost a race for secretary of state in 2014. He co-founded New Era Colorado, a left-leaning group that encourages young residents to register to vote and cast ballots.

“Joe Neguse has long been a powerful ally of the environmental movement here in Colorado, by helping thousands of young people register to vote and promoting renewable energy in our state,” said Carrie Curtiss, acting executive director of Conservation Colorado.

Neguse welcomed the endorsement.

“When I announced my campaign, I said that tackling climate change was one of the central reasons I got into this race, which is why LCV’s endorsement means so much to me” he said in a statement released by his campaign. “Our climate is at grave risk, and a new generation of leaders must tackle this problem head on. That means taking bold action on renewable and clean energy and protecting the incredible public lands in the 2nd Congressional District and beyond.”

The other Democrats running in the district are Nederland Mayor Kristopher Larsen and former Boulder Democratic Party Chairman Mark Williams. Gun control activist Ken Toltz suspended his campaign Monday, citing the demands of a serious health issue in his immediate family. Republican Peter Yu, a political newcomer, announced last week he’s running for the GOP nomination.

LCV Action Fund raised more than $8.3 million for candidates last cycle and says it’s helped elect 73 senators and 331 House members since 1994.