Breton and Picasso 

Your clarification was in order and I thank for that; Breton was, indeed, a Trotskyist and a bitter enemy of Stalin. As you said, this helps to explain his remark to Picasso.

I would make one correction: Breton was a "Trotskyist". From the Wikipedia website http://en.wikipedia.org/wiki/Trotskyism,  "In France, 10% of the electorate voted in 2002 for parties calling themselves Trotskyist" (my emphasis). I don't think the "Trotskyite" spelling occurs anywhere this Wikipedia page: "Trotskyist" is used throughout, and establishes it as the accepted spelling. 

The same wiki site says: "Today, in the English language an advocate of Trotsky's ideas is usually called a "Trotskyist" while Trotskyism's opponents usually refer to them pejoratively as a "Trotskyite" or "Trot".[5]" In the same way, one is a "Stalinist", not a "Stalinite" whether one likes or dislikes Stalin. 

Advocate or not, let's not use any terms that have a desparaging tone. I know you didn't mean it as such; I used "Trotskyite" myself for many years.
Let's use "Trotskyist" if only for the sake of consistency.Mysweetoldetc.