Late upset for the USA involving Republican
I believe the answer is:
after hours
'late' is the definition.
(I've seen this before)
'upset for the usa involving republican' is the wordplay.
'upset' indicates anagramming the letters.
'involving' means one lot of letters goes inside another.
'republican' becomes 'r' (abbreviation).
'for'+'the'+'usa'='fortheusa'
'fortheusa' anagrammed gives 'afterhous'.
'afterhous' enclosing 'r' is 'AFTER HOURS'.
(Other definitions for after hours that I've seen before include "when we're not open" , "Late" .)