Vladimir Ilyich Ulyanov was Russian. 
Josef Vissarionovich Djugashvili was Georgian.
And was on the cusp of purging Jewish people when he died. 
Nikita Sergeyevich Khrushchev was Russian. 
Correct me if I'm wrong, but I do not think Mao Zedong, Kim Il Sung, Ho Chi Minh, and Pol Pot were Jewish, either. 
There were ethnically Jewish leaders in Socialism - including Marx himself - but their ethnic background was irrelevant to their philosophy and politics (except, possibly, as a rejection of their ethnic culture).
Let me see if I understand you,ok? Marx and the other Jews who were the driving force behind the 1917 revolution,including that wonderful human being and 1st man to head he NKVD, Felix Edmundovich Dzerzhinsky were just "Socialists",not Communists?
BTW,a socialist is nothing more than a communist that lacks conviction.