Sanders had been the solid second choice of S.C. voters in previous polls. But Warren reversed deficits with Sanders among men, women, voters under age 50 and, most importantly, African Americans who make up a majority of Democrats going to the polls.

And she now leads the race among voters ages 18 to 34, a spot previously held by Sanders.

Buttigieg’s surprising run continues to strengthen.

The field’s youngest candidate, who was not even in the first S.C. survey taken in February, has moved up spots in each of the past two polls. This month, he received upticks in support from voters ages 65 and older, as well as independents.

Most notable is Buttigieg’s growing support from black voters. He collected 6 percent African American support, good enough for fourth this month, after he received none in May.