To be accurate, he visited in 1919 when the Soviet Union didn’t exist. It was a Civil War with Bolsheviks fighting the White Russians. What he saw that was positive in that brutal conflict is anyone’s guess.
Yes, I had forgotten. My memory is that he was speaking of the Bolsheviks and believed that they were going to win. I don’t recall that he associated with Mensheviks, but perhaps I don’t recall accurately.