The results from Saturday’s primary in South Carolina indicate that Senator Bernie Sanders of Vermont faces trouble winning the trust of African-Americans.

Mr. Sanders won only 16 percent of the vote among African-Americans, according to early exit polls results from Edison Research, and there were signs that his message simply had not gotten through.

About a third of black voters said that Mr. Sanders was not liberal enough for them, about three times more than said so about Mrs. Clinton, despite the fact that Mr. Sanders’s policies tend to be further to the left.

Four in five African-American voters said they felt Mrs. Clinton’s policy stances were just about right. Less than half said so about Mr. Sanders’s policies.

Notably, less than half of black participants in Saturday’s primary identified as liberal. Even among African Americans whose primary concern was income inequality — a staple of Mr. Sanders’s platform — Mrs. Clinton beat him by more than three to one.

Another ominous sign for Mr. Sanders: While almost nine in 10 black voters said they would trust Mrs. Clinton to handle race relations, nearly half said they would not trust him on race.

Eighty percent of African-American voters said that considerations of race relations were an important factor in their vote. (A similar number of whites said the same.)