I'd love to support president's code of chivalry (7)
I believe the answer is:
bushido
'code of chivalry' is the definition.
'bushido' can be an answer for 'code' (I have seen 'honourable code' mean 'bushido' so perhaps 'code' could also mean 'bushido'). I am unsure of the 'of chivalry' bit.
'i'd love to support president's' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'to support' says to put letters next to each other (in a down clue, some letters hold up others).
'president' becomes 'bush' (George H W Bush or George W Bush).
'id'+'o'='ido'
'ido' put after 'bush' is 'BUSHIDO'.
Can you help me to learn more?
(Other definitions for bushido that I've seen before include "chivalric code" , "Code of the Japense Samurai" , "honourable code" , "Code for old military" , "Japanese code of chivalry" .)