CREATE TABLE table_11791 ("Name" TEXT, "Appointed/Elected" TEXT, "Term expires" TEXT, "Appointing Governor" TEXT, "Governor's Party Affiliation" TEXT)

What is the party affiliation of Thomas D. Waterman, whose appointing governor is Terry Branstad?
SELECT "Governor's Party Affiliation" FROM table_11791 WHERE "Appointing Governor" = 'terry branstad' AND "Name" = 'thomas d. waterman'
SELECT "Governor's Party Affiliation" FROM "table_11791" WHERE "Appointing Governor" = 'terry branstad' AND "Name" = 'thomas d. waterman'