Blur out Republic? It's a long story! (4)
I believe the answer is:
epic
'a long story' is the definition.
(eg an epic poem)
'blur out republic?' is the wordplay.
'out' indicates named letters should be taken away.
'republic' with 'blur' taken out is 'EPIC'.
'it's' is the link.
(Other definitions for epic that I've seen before include "Long poem telling of great events" , "Impressively great" , "Long literary work about great events" , "Ben Hur, say" , "Large-scale" .)