The South Carolina property tax in excess of the $10,000 SALT cap does not appear to be deductible on the SC return.
The effect of the $10,000 cap is felt on Schedule A, so that federal taxable income includes the deductions taken on Schedule A.
The SC return starts with federal taxable income (unlike many states that start with federal adjusted gross income (AGI).
There is a large number of additional subtractions from South Carolina income, but I do not see one for property taxes at all, much less for property taxes not allowed to be taken on the federal return.
Please look at the South Carolina instructions for SC subtractions - https://dor.sc.gov/forms-site/Forms/SC1040Instr_2018.pdf
