CREATE TABLE table_18132 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Results" TEXT, "Candidates" TEXT)

Who were the candidates in the district first elected in 1998 whose incumbent ended up being Paul Ryan?
SELECT "Candidates" FROM table_18132 WHERE "First elected" = '1998' AND "Incumbent" = 'Paul Ryan'
SELECT "Candidates" FROM "table_18132" WHERE "First elected" = '1998' AND "Incumbent" = 'Paul Ryan'