Who was the incumbent that was first elected in 1892 and retired to run for the senate democratic hold?
CREATE TABLE "south_carolina" (
  "district" text,
  "incumbent" text,
  "party" text,
  "first_elected" text,
  "result" text
);
SELECT "incumbent" FROM "south_carolina" WHERE "first_elected"='1892' AND "result"='retired to run for the senate democratic hold';