President -- the man's a Democrat (4)

I believe the answer is:

head

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'president' is the definition.
(thesaurus)

'the man's a democrat' is the wordplay.
'the man' becomes 'hea' (I can't justify this - if you can you should give a lot more credence to this answer).
'a democrat' becomes 'd'.
'hea'+'d'='HEAD'

Can you help me to learn more?

(Other definitions for head that I've seen before include "Leader; stream source" , "Promontory; foam" , "Leader; front" , "Be in charge of; (come to) crisis" , "See 14" .)

I've seen this clue in The Telegraph.

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