CREATE TABLE table_21167 ("District" TEXT, "Vacator" TEXT, "Reason for change" TEXT, "Successor" TEXT, "Date successor seated" TEXT)

In the district Wisconsin 2nd, what was the reason for change?
SELECT "Reason for change" FROM table_21167 WHERE "District" = 'Wisconsin 2nd'
SELECT "Reason for change" FROM "table_21167" WHERE "District" = 'Wisconsin 2nd'