CREATE TABLE table_28878 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" TEXT, "Result" TEXT, "Candidates" TEXT)

Who were the candidates in the Kentucky 9 district?
SELECT "Candidates" FROM table_28878 WHERE "District" = 'Kentucky 9'
SELECT "Candidates" FROM "table_28878" WHERE "District" = 'Kentucky 9'