CREATE TABLE table_18554 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" FLOAT, "Result" TEXT, "Candidates" TEXT)

What party does the incumbent from the Ohio 20 district belong to?
SELECT "Party" FROM table_18554 WHERE "District" = 'Ohio 20'
SELECT "Party" FROM "table_18554" WHERE "District" = 'Ohio 20'