Adherent of far left or moderate movement (4)

I believe the answer is:

trot

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'moderate movement' is the definition.
(I've seen this before)

I don't understand the remainder of the clue.

(Other definitions for trot that I've seen before include "Hurry along" , "Horse's steady pace" , "Jogging pace" , "Not dead" , "Fairly fast pace of a horse" .)

I've seen this clue in The Times.

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