CREATE TABLE table_3615 ("District" TEXT, "Incumbent" TEXT, "Party" TEXT, "First elected" TEXT, "Result" TEXT, "Candidates" TEXT)

Name the incumbent for lost re-election democratic-republican hold
SELECT "Incumbent" FROM table_3615 WHERE "Result" = 'Lost re-election Democratic-Republican hold'
SELECT "Incumbent" FROM "table_3615" WHERE "Result" = 'Lost re-election Democratic-Republican hold'