Several polls conducted last month showed Harris, whose father is Jamaican, losing a dozen percentage points.
In a CNN/SSRS poll conducted in late May, Harris polled eight percent. But that number spiked to 17 percent following a June debate for Democratic presidential candidates.
Last month her CNN/SSRS poll number dropped to five percent.
Former U.S. Vice President Joe Biden maintained his lead in most polls last month, ending with 29 percent in the latest CNN/SSRS. He’s followed by Bernie Sanders (15 percent) and Elizabeth Warren (14 percent). Pete Buttigieg is tied with Harris at five percent.
Harris is currently a senator from California. She has already qualified for the next Democratic debate.
Wayne Messam, a second Caribbean American trying to win the Democratic nomination to challenge Republican President Donald Trump, has not made a significant impact on the polls. The mayor of Miramar, Florida, home to a large Caribbean American community, was not invited for the two recent Democratic debates after failing to meet the criteria for qualification, but is still listed among the candidates.
Meanwhile, several candidates have withdrawn from the race for the Democratic nomination. At one point more than 20 candidates were in the field.