Active party member, one welcomed by most of respectful company (8)

I believe the answer is:
politico
'active party' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe there's a link between them I don't understand?
'member one welcomed by most of respectful company' is the wordplay.
'member one' becomes 'i' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'welcomed by' is an insertion indicator (letters welcomed inside).
'most of' means to remove the last letter.
'respectful' becomes 'polite' (I've seen this in another clue).
'company' becomes 'co' (abbreviation).
'polite' with its final letter taken away is 'polit'.
'polit'+'co'='politco'
'i' placed within 'politco' is 'POLITICO'.
Can you help me to learn more?
(Other definitions for politico that I've seen before include "party animal?" , "Party man" , "Parliamentary member" , "Party type" , "statesman" .)
