Conservative thug shows political muscle? (5)
I believe the answer is:
clout
'political muscle?' is the definition.
(I've seen this in another clue)
'conservative thug' is the wordplay.
'conservative' becomes 'C' (UK political abbreviation).
'thug' becomes 'lout'.
'c'+'lout'='CLOUT'
'shows' is the link.
(Other definitions for clout that I've seen before include "hit hard" , "Influence or power" , "Political influence - flat-headed nail" , "Swipe" , "Punch; influence" .)