The lack of diversity among the 2020 candidates looms over the Democratic Debate as Buttigieg points out the \'7 white people on this stage talking about racial justice\'

The Democratic presidential candidates debate in South Carolina on Tuesday night.

Towards the top of the debate, former South Bend mayor Pete Buttigieg addressed the uncomfortable truth hovering over the proceedings.

"There's 7 white people on this stage talking about racial justice," Buttigieg said.

After starting out the 2020 primary with a historically diverse field of candidates, the field has since winnowed to be nearly entirely white. Only white candidates qualified for Tuesday night's debate, ,with Congresswoman Tulsi Gabbard excluded from the debate due to low polling. Past debates have also been criticized for failing to include candidates like Andrew Yang, who criticized the qualifying process before ending his campaign earlier this year.

"None of us have the experience, the lived experience of, for example, walking down the street or, in a mall, and feeling eyes on us regarding us as dangerous…just because of the color of our skin," Buttigieg continued, emphasizing that he came to the subject with "humility."

The candidates spent the next hour attempting to prove to black voters - who make up a significant share of South Carolina's Democratic electorate and, nationally, comprise the party's most loyal voting block - that they were capable of addressing their specific challenges and policy needs.

Joe Biden invoked the Charleston Church shooting while attacking Sanders' record on guns. Elizabeth Warren condemned redlining. Michael Bloomberg's stop-and-frisk policy came under scrutiny.

Investor Tom Steyer called for "reparations for slavery" and a "formal commission on race to retell the story of the last 400 plus years in Ameirca, of African Americans."

"Every single policy in the United States has a gigantic subtext of race," he said. "We're talking about education, we're talking about criminal justice, we're talking about loans." 

The candidates' performance in South Carolina, particularly among black voters, will be seen as a test of whether they can win the rest of the Democratic electorate.