I think your estimate of Einstein's political sympathies is mistaken. Einstein was first and foremost a humanist. He was not a rabid anything, especially not a rabid political theorist.
He was forced to leave Europe in 1933, and, after arriving in Princeton, never left there. He became an American citizen in 1940.
He was a gentle man who sought peace and well-being for all, but who also could see clearly enough the nature of the threat posed to the world by Hitler and the Nazis. That is why he agreed to sign the letter posted above by IonImplantGuru.
Suggest you review the link shown above or simply go to Google and type in Einstein and communism. Like most Communists he was always in favor of peace when Stalin was building his war machine and taking over half of Europe.
This love of peace disappeared in the case of Nazi Germany since it threatened and then made war on the Socialist Paradise of Stalin's Russia.
I have no doubt he was a gentle man but his views on politics were moronic. Like celebrities today, he was given a lot of ink because the left-wing press liked him.
Being a scientist takes a particular brand of intelligence, like being great at math, and it has nothing to do with wise about law,philosophy or politics.