Film about Long Island supporter of Israel losing the head with politician in government alliance (12)
I believe the answer is:
coalitionist
'politician in government alliance' is the definition.
The definition suggests a singular noun which matches the answer.
'film about long island supporter of israel losing the head' is the wordplay.
I cannot really understand how this works, but
'film' could be 'it' and 'it' is found within the answer.
'about' could be 'on' and 'on' is found in the answer.
'long' could be 'l' and 'l' is located in the answer.
'island' could be 'is' and 'is' is found in the answer.
'of' could be 'o' and 'o' is found in the answer.
This may be the basis of clue (or it may be nonsense).
'with' acts as a link.
Can you help me to learn more?
(Another definition for coalitionist that I've seen is " one seeking alliance".)