CREATE TABLE table_18365 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" TEXT, "Result" TEXT, "Candidates" TEXT)

What party did the incumbent from the Illinois 12 district belong to?
SELECT "Party" FROM table_18365 WHERE "District" = 'Illinois 12'
SELECT "Party" FROM "table_18365" WHERE "District" = 'Illinois 12'