"Dickerson" is the correct answer:
Joyce Dickerson (DEM) 37.06% 457,435
Brad Hutto (DEM) 36.80% 454,651
Wrong!
You've neglected to add in the votes Hutto got on the Working Families line. South Carolina has electoral fusion and the combined votes Hutto got from both of the parties that endorsed him is what counts.
Victor Kocher (LIB) 2.72% 33,654
Thomas Ravenel (PET) 3.84% 47,413
Brad Hutto (DEM) 36.81% 454,938
Brad Hutto (WFM) 1.95% 24,058Lindsey Graham (REP) 54.30% 670,992
Write-In (NON) 0.39% 4,771
Add them together and Hutto has 478,996 votes and 38.76% of the vote which is more than Dickerson
Joyce Dickerson (DEM) 37.07% 457,720
Tim Scott (REP) 61.14% 754,937
Jill Bossi (AMR) 1.75% 21,562
Write-In (NON) 0.04% 534
The same problem affects your map. Add in the WF votes and Hutto also did better than Dickerson in Beaufort, McCormick, Newberry and York counties.
Even in the counties where Dickerson did better than Hutto her margin was razor thin.
Chester 3563 to 3511 (52 votes)
Lancaster 6914 to 6905 (9 votes)
Oconee 3923 to 3896 (27 votes)
Union 3069 to 3039 (30 votes)
Williamsburg 7117 to 7115 (2 votes)
The total margin in all the counties she did better than Hutto in, 120 votes, is more than swamped by the difference in her home county of Richland, which cast 66,089 votes for Hutto compared to only 64,722 votes for her.