Turnout in Tuesday's primaries hit at least 17 percent of registered voters, which was better than 4 years ago.
The League of Women Voters of the Charleston Area had pushed to increase turnout above the 16 percent mark, which was the threshold achieved in the 2014 party primaries.
That meant 84 percent of eligible voters stayed home that year.
"Democracy can't function when citizens don't participate," the group said.
Turnout was 24 percent in 2010.
South Carolina has more than 3 million registered voters.