Why do you think that Scott out-performed Graham?
Lindsey Graham: 672,941 (54.3%)
Brad Hutto: 480,933 (38.8%)
Tim Scott: 757,215 (61.1%)
Joyce Dickerson: 459,583 (37.1%)
I'm offering these choices as the two most likely scenarios in my mind:
(1) Conservative Republicans withholding votes for Graham or
(2) more blacks voting for Scott?
(1) can't be true since there were more raw votes in the Graham race in the Scott race. (2) could be true, but the exit polls show Scott outperforming Graham with whites.
I would have thought that Graham + Ravenel would run ahead of Scott, since Graham is a longer incumbent, and on balance is more moderate than Scott (though Graham has had some right-wing rhetoric), and that some racist whites wouldn't vote for Scott.