Which parties have delegates in both the "Appropriations" committee and the "Economic Matters" committee?
SELECT T2.Party FROM election AS T1 JOIN party AS T2 ON T1.Party  =  T2.Party_ID WHERE T1.Committee  =  "Appropriations" INTERSECT SELECT T2.Party FROM election AS T1 JOIN party AS T2 ON T1.Party  =  T2.Party_ID WHERE T1.Committee  =  "Economic Matters"
parties with delegates in both committees; INTERSECT to find common elements; Appropriations and Economic Matters are committee names;