Sen. Bernie Sanders Bernie SandersButtigieg stands in as Pence for Harris's debate practice Bernie Sanders warns of 'nightmare scenario' if Trump refuses election results Harris joins women's voter mobilization event also featuring Pelosi, Gloria Steinem, Jane Fonda MORE (I-Vt.) released another radio ad Tuesday that highlights his push for criminal justice reform as he seeks to make inroads in South Carolina.

The Democratic presidential candidate has been ramping up his play for African-American voters in the early-voting state, and the radio ad seeks to spotlight his calls to end mass incarceration and fight racial inequality. In 2008, more than half of the Democratic primary electorate in South Carolina was black.

ADVERTISEMENT

"Millions of lives are being wrecked, families are being torn apart and we are spending huge sums of taxpayer money locking people up," Sanders says in the new radio ad, “One Candidate.”

He continues, “And it makes a lot more sense for us to be investing in education and jobs rather than in jails and incarceration.”

The new radio ad, which is the third in this expanded outreach, will run for 10 days and air on radio stations in Charleston, Columbia, Florence, Myrtle Beach and Greenville.

"Our third radio ad is part of a broader effort to engage with African-Americans in South Carolina and spread Sen. Sanders' grassroots message to local communities," Sanders state director Chris Covert said in a statement. "Sanders speaks honestly and consistently to the issues that directly impact South Carolinians and has a proven record of fighting on behalf of hardworking Americans struggling in our rigged economy."

Both Sanders and Democratic presidential front-runner Hillary Clinton Hillary Diane Rodham ClintonButtigieg stands in as Pence for Harris's debate practice Senate GOP sees early Supreme Court vote as political booster shot Poll: 51 percent of voters want to abolish the electoral college MORE have been making a push to court the African-American vote.

Both candidates have met with Black Lives Matters organizers and with family members of the victims who died in incidents with police. Sanders also recently did a campaign swing through southern states including South Carolina and Georgia.

But when it comes to polling and endorsements, Clinton has staked out a comfortable lead over Sanders.

Clinton leads Sanders nationally, 56 percent to 31.3 percent, and edges him out with a larger gap in the South Carolina Democratic primary polls, 71 pervent to 21.3 percent, according to the latest RealClearPolitics averages.

She also snagged more than 30 endorsements from Congressional Black Caucus members.