CREATE TABLE table_18589 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" FLOAT, "Result" CLOB, "Candidates" CLOB)

Who were the candidates when Sid Simpson was the incumbent?
SELECT "Candidates" FROM table_18589 WHERE "Incumbent" = 'Sid Simpson'
SELECT "Candidates" FROM "table_18589" WHERE "Incumbent" = 'Sid Simpson'