One can simply look at the last names of the founding members of the Menchaviks and the Bolshiviks and count the amount of Jewish people and do the math.

There was about 3 times more jews in the menchaviks and the only prominent Jew in the Bolshiviks leadership was Trotsky whom started as a menchavik and switched sides.

Look it up and get out your counting fingers if you don't belive me and you can figure it out yourself.