>Wolfie was in IS?!?!?
No. But according to a wikipedia he was a speaker at Social Democrats USA conferences in the 1970s. That doesn't mean he was a Shachtmanite or anything, perhaps just that they found his foreign policy views compatible.
On M.P.'s question about whether Rivera was with Trotsky or Stalin when he painted the mural: he painted it in 1947-48. Rivera and Trotsky had quarrelled before Trotsky's assassination. Reportedly Rivera was trying to get back with the PCM by the late 40s but wasn't accepted back until the early 50s.
The Sandwichman