Conservative leader heads more hopeful staff... (7)
I believe the answer is:
crosier
'staff' is the definition.
(crosier is a kind of staff)
'conservative leader heads more hopeful' is the wordplay.
'leader' indicates taking the first letters.
'heads' means one lot of letters go next to another (some letters go ahead of others).
'more hopeful' becomes 'rosier' ('rosy' can be a synonym of 'hopeful').
The initial letter of 'conservative' is 'c'.
'c'+'rosier'='CROSIER'
(Other definitions for crosier that I've seen before include "Bishop's crook" , "A bishop's staff as symbol of office" , "one's hooked!" , "Ecclesiastical staff" , "Staff carried by a bishop" .)