Diehard constituents stay out of sight then make the leap (9)
I believe the answer is:
hidebound
'diehard constituents stay' is the definition.
I can't tell whether this definition defines the answer.
'out of sight then make the leap' is the wordplay.
'out of sight' becomes 'hid' (I've seen this in another clue).
'then make' becomes 'e' (I can't justify this - if you can you should give a lot more credence to this answer).
'the leap' becomes 'bound' (synonyms).
'hid'+'e'+'bound'='HIDEBOUND'
Can you help me to learn more?
(Other definitions for hidebound that I've seen before include "Narrow-minded - ultra-conservative" , "Bigoted" , "very conservative" , "Narrow" , "Splash (with liquid)" .)