Former Vice President Joe Biden Joe BidenMomentum growing among Republicans for Supreme Court vote before Election Day Trump expects to nominate woman to replace Ginsburg next week Video of Lindsey Graham arguing against nominating a Supreme Court justice in an election year goes viral MORE attributed his drop in African American support ahead of the South Carolina primary to billionaire Tom Steyer Tom SteyerTV ads favored Biden 2-1 in past month Inslee calls Biden climate plan 'perfect for the moment' OVERNIGHT ENERGY: Trump administration finalizes plan to open up Alaska wildlife refuge to drilling | California finalizes fuel efficiency deal with five automakers, undercutting Trump | Democrats use vulnerable GOP senators to get rare win on environment MORE’s spending in the state in a Sunday interview on “Face the Nation.”

“What’s happening is you have Steyer spending millions of dollars out campaigning there, so I think a lot’s happening in terms of the amount of money being spent by billionaires to try to cut into the African American vote,” Biden told CBS’ Margaret Brennan.

When Brennan described South Carolina, the first primary state where African Americans are a major bloc of the electorate, as Biden’s “firewall,” the former vice president responded, “You said it’s my firewall, I’ve never said that. I’ve said I’m going to do well there.”

“You guys can do all the pontificating about what it means," Biden said. "That’s not my job, my job is to go in and make the best I can, I think we’re going to do well, I think we’re going to go on to super Tuesday and do very well.”

Biden also doubled down on calling on Sen. Bernie Sanders Bernie SandersNYT editorial board remembers Ginsburg: She 'will forever have two legacies' Two GOP governors urge Republicans to hold off on Supreme Court nominee Sanders knocks McConnell: He's going against Ginsburg's 'dying wishes' MORE (I-Vt.) to disavow abusive supporters or those claiming to be supporters, which the Vermont senator has done on multiple occasions, saying “that’s Trump-like stuff.”

The former vice president went on to implicitly contrast himself with both President Trump Donald John TrumpUS reimposes UN sanctions on Iran amid increasing tensions Jeff Flake: Republicans 'should hold the same position' on SCOTUS vacancy as 2016 Trump supporters chant 'Fill that seat' at North Carolina rally MORE and Sanders in the wake of reports that Russia had acted to intervene on the two candidates’ behalf.

“The Russians don’t want me to be the nominee … no one’s helping me to try to clinch the nomination.”

Biden also claimed Facebook had alerted him to bot traffic attempting to spread misinformation about him.