It is interesting seeing socialists and communists praising Hitler in 1939 to 1941 and suddenly declaring Hitler to be enemy number one. Even before 1939 many socialists were fans of fascism. In Orwell's 1984, the quick shift over who was the enemy without anyone being allowed to mention that the change occured was making fun of the quick change by British communists in 1941.
My theory is that it’s relative. You can be politically to the right or left of any position. There are conservatives who are to the right of me and there are conservatives who are to the left.
Objectively, fascism is big government socialism, so that makes it on the left in absolute terms. However, liberals claim that it’s right-wing because, to them, they are to the left of fascism which makes them communists or nearly so.