Here are the conditions:
A) The ruler need not be Trotsky
B) The Trotskyite influence cannot be merely ephemeral, rather the constitution is developed by Trotskyites
C) Stalin must still be ruler of the USSR from 1927 through WWII
D) The regime must clearly identify itself as Trotskyite, either being establishing after his exile and further articulation of theory, or, if established as a Leninist regime before his exile, it must identify its sympathy with Trotsky's theories within a decade of "Trotskyism" becoming a political sin in the USSR.