CREATE TABLE table_730 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Result" TEXT, "Candidates" TEXT)

Who were the candidates in the district whose incumbent is Joe Waggonner?
SELECT "Candidates" FROM table_730 WHERE "Incumbent" = 'Joe Waggonner'
SELECT "Candidates" FROM "table_730" WHERE "Incumbent" = 'Joe Waggonner'