CREATE TABLE county (county_id NUMBER, county_name CLOB, population NUMBER, zip_code CLOB)
CREATE TABLE party (party_id NUMBER, year NUMBER, party CLOB, governor CLOB, lieutenant_governor CLOB, comptroller CLOB, attorney_general CLOB, us_senate CLOB)
CREATE TABLE election (election_id NUMBER, counties_represented CLOB, district NUMBER, delegate CLOB, party NUMBER, first_elected NUMBER, committee CLOB)

Find the committees that have delegates both from from the democratic party and the liberal party.
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"
SELECT "T1"."committee" FROM "election" "T1" JOIN "party" "T2" ON "Democratic" = "T2"."party" AND "T1"."party" = "T2"."party_id" INTERSECT SELECT "T1"."committee" FROM "election" "T1" JOIN "party" "T2" ON "Liberal" = "T2"."party" AND "T1"."party" = "T2"."party_id"