Billionaire philanthropist Tom Steyer announced his first presidential endorsement from an ex-lawmaker on Tuesday.

Former South Carolina state Rep. Harold Mitchell (D) endorsed Steyer, saying in a statement that he “is the best candidate that can address climate and environmental justice issues.”

{mosads}”He is the only authentic candidate left who has a track record of solutions that is ready for the climate and environmental justice battle,” Mitchell added. “That is why I am on his team one hundred percent.”

Mitchell served in the South Carolina House for 13 years before retiring in 2017 because of health issues. He previously founded a nonprofit called the ReGenesis Project, which focuses on fighting environmental racism.

Tuesday’s announcement marks Steyer’s first endorsement from a current or former lawmaker since launching his White House bid in July, according to his campaign.

South Carolina plays a key role in the Democratic presidential primary as an early voting state.

Steyer over the weekend became the 11th candidate to qualify for the October debate when he garnered at least 2 percent in a fourth Democratic National Committee-approved poll.

He has used his personal wealth to funnel more than $10 million into digital and television advertisements since joining the crowded field, propelling him past several candidates with more political experience.