Commitment to Party welcoming free vote for one new leader (8)
I believe the answer is:
devotion
'commitment' is the definition.
(devotion is a kind of commitment)
'party welcoming free vote for one new leader' is the wordplay.
'party' becomes 'di' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'welcoming' is an insertion indicator (in sense of 'inviting in').
'free' is an anagram indicator.
'for' is a charade indicator (letters next to each other).
'leader' indicates taking the first letters.
The initial letters of 'one new' is 'on'.
'vote' with letters rearranged gives 'evot'.
'di' going around 'evot' is 'devoti'.
'devoti'+'on'='DEVOTION'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for devotion that I've seen before include "Feelings of ardent love" , "Great love" , "Dedication" , "Commitment to some purpose, religion say" , "Religious zeal" .)