Guarantee Republican dismissed result (5)
I believe the answer is:
ensue
'result' is the definition.
(to ensue is to occur or result)
'guarantee republican dismissed' is the wordplay.
'guarantee' becomes 'ensure' (synonyms).
'republican' becomes 'r' (abbreviation).
'dismissed' suggests deleting specific letters.
'ensure' with 'r' taken away is 'ENSUE'.
(Other definitions for ensue that I've seen before include "Happen as a result, follow ( 5)" , "Occur as a result (of)" , "Come to pass" , "Occur afterwards" , "Follow later" .)