Times leads with editor's rant about socialism (4)
I believe the answer is:
eras
'times' is the definition.
(an era is a time or period)
'leads with editor's rant about socialism' is the wordplay.
I cannot really understand how this works, but
'about' could be 'a' (abbreviation in Chambers) and 'a' is present in the answer.
The remaining letters 'ers' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for eras that I've seen before include "typeface" , "Periods of time" , "At least two times" , "Epochs" , "Long and distinct periods of history" .)