Question: Which committees have delegates from both parties, please?
SQL: SELECT T1.Committee FROM election AS T1 JOIN party AS T2 ON T1.Party   =   T2.Party_ID WHERE T2.Party   =   "Democratic" INTERSECT SELECT T1.Committee FROM election AS T1 JOIN party AS T2 ON T1.Party   =   T2.Party_ID WHERE T2.Party   =   "Liberal"