How many parties have at least two records?
select count ( * ) from ( select party from party group by party having count ( * ) > = 2 )
What are those parties?
select party from party group by party having count ( * ) > = 2
Who are the comptroller of those individuals?
select comptroller from party where us_senate in ( select us_senate from party where party in ( select party from party group by party having count ( * ) > = 2 ) )