CREATE TABLE table_18411 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Result" TEXT, "Candidates" TEXT)

Who ran in the race for Jack Brooks' seat?
SELECT "Candidates" FROM table_18411 WHERE "Incumbent" = 'Jack Brooks'
SELECT "Candidates" FROM "table_18411" WHERE "Incumbent" = 'Jack Brooks'