Poll: Sanders gains ground on Biden with black voters nationally

According to the newly released data, Biden has the support of 31 percent of black Democratic primary voters, while Sanders captures the backing of 29 percent.

The NBC News/WSJ poll used an oversample of black voters to gain greater insight into their views of the 2020 field. Because the margin of error for black Democratic primary voters alone — a sample size of 139 respondents — stands at a high 8.31 percent, it is difficult to differentiate the true levels of support for each of the candidates.

Still, the close margin shows that Sanders has made inroads in a community previously dominated by Biden; aggregated data from 2019 shows that Biden led Sanders among these voters by as much as 30 percentage points in NBC News/WSJ national polls last year.