Boldness offending Democrat in party (7,2)
I believe the answer is:
derring do
'boldness' is the definition.
(I've seen this before)
'offending democrat in party' is the wordplay.
'offending' becomes 'erring' (err can mean to offend or sin).
'democrat' becomes 'd'.
'in' indicates putting letters inside.
'party' becomes 'do' (do is a kind of party).
'erring'+'d'='erringd'
'erringd' placed inside 'do' is 'DERRING-DO'.
(Other definitions for derring do that I've seen before include "bold action" , "Audacious action" , "heroic action" , "Brave action" , "Brave actions" .)