1) Abandonment 2) Communist theory 3) Defection 4) Desertion 
A deviationist is a person who expresses a deviation: an abnormality or departure. In Stalinism, deviationism is an expressed belief which is not in accordance with official party doctrine for the time and area. Accusations of deviationism often led to purges. Forms of deviationism included revisionism, dogmatism, bourgeois nationalism, and rootle...
[n] - ideological defection from the party line (especially from orthodox communism)
noun ideological defection from the party line (especially from orthodox communism)
(in Communist ideology) departure from accepted party policies or practices. · any deviation from official policy.