Some black voters are having reservations about the 2020 Democrats you hear about all the time.

Driving the news: A new poll from the Black Economic Alliance of 1,003 black Americans found that between 27% and 33% of those surveyed "have reservations" about or are "very uncomfortable" with Cory Booker, Elizabeth Warren, Beto O'Rourke, and Pete Buttigieg as presidential candidates.

Between the lines: Things are even more bleak when you look at the percentage of people who don't know who these same candidates are. Nearly half of black Americans surveyed don't know Mayor Pete and 37% said they don't know Beto.

What's more, while Bernie Sanders came in second place in this poll, almost one-third of all people surveyed — of whom only 7% said they didn't know him — aren't totally comfortable with him as a candidate.

Why it matters: It's still early in the 2020 cycle, but this survey suggests most leading Democratic candidates — even minority candidates like Booker and Kamala Harris — will have to work harder to get support from black voters.

What they're saying: "We live in a world where we follow politics 24 hours a day, but that’s not the reality for most Americans," said Akunna Cook, executive director of the Black Economic Alliance, which is hosting a presidential forum this weekend in South Carolina.

"We know that black Americans are going to make a difference for who gets in the White House in 2020," she said. "They’re hungry for a candidate that will speak to the issues that are central to them."

Go deeper: 2020 Democrats are ready to talk about racial inequality.