Squirm with embarrassment initially about Republican (6)
I believe the answer is:
writhe
'squirm' is the definition.
(synonyms)
'with embarrassment initially about republican' is the wordplay.
'initially' says to take the initial letters.
'about' means one lot of letters goes inside another.
'republican' becomes 'R' (abbreviation in US politics).
The initial letter of 'embarrassment' is 'e'.
'with'+'e'='withe'
'withe' placed around 'r' is 'WRITHE'.
(Other definitions for writhe that I've seen before include "Twist as in pain" , "worm" , "Twist in agony" , "Struggle" , "Wriggle" .)