I believe that the Eastern European Jewish cultural memory reflexively equates a devout "Christian" with the East European "Christian" (in the loose sense of the word) mobs that devastated Jewish communities in Czarist Russia and Poland in the 19th and early 20th Century pogroms.
Their ancestral memory equates a devout "Christian" with :
These pogroms were not only tolerated but sometimes even encouraged by Czarist authorities.
It is no wonder then that Eastern European Jews were such a large component of the early Communist movement. In theory at least, Communism offered the overthrow of the hated Czarist regime, the destruction of the "Christian" religion whose clerics encouraged the pogroms and the establishment of a secular state with complete equality for Jews.
However, theory and practice are two different things. Over 90% of the Jews who fled the Czarist Russian pogroms ended up in the United States. Most of those came before the birth of the Soviet Union. They never saw the evils of the Communist system first hand.
So, the ancestral mind set becomes:
Czar = Bad.
Communism = Enemy of the Czar = Good.
Christians who take religion seriously = Pogrom = Dead Jews = Really Bad.
Secularism = No Christians = No Pogroms = Really Good.
Of course, the 21st Century American Bible Belt Protestant, who doesn't know a pogrom from a pierogi, is a totally different animal from the 19th Century Russian "Christian" peasant burning down great-garndpa's village.
However, the Eastern European Jewish ancestral memory A.) Does not realize that or B.) Doesn't want to take any chances.
This also explains the Eastern European Jewish fascination with the Left.
Large numbers of Eastern European Ashkenazi Jews were seduced by Communism because it was the enemy of the Czarist Russia under which they had suffered for so long. The Eastern European Jews followed the philosophy of, "The enemy of my enemy is my friend."
You won't find the same infatuation with Communism among Sephardic Jews.
Unfortunately, this love affair with Communism was brought to America by late 19th Century and early 20th Century Jewish immigrants before they had a chance to see for themselves what a horror Communism was. Throughout the 20th Century, the children and grandchildren of many of these early Ashkenazi Jewish immigrants were raised as "Red Diaper Babies" without questioning whether Grandpa's love of Bolshevism in the 1910's was justified.
The "Red Diaper" Jewish generations are now dying off from old age. The new Ashkenazi Jewish generations are seeing for themselves that the Left has embraced the new enemies of America which also happen to be the enemies of the Jews.
Following the "The enemy of my enemy is my friend" phenomenon, I see greater numbers of the younger Jewish generation leaving Grandpa's Bolshevism behind and coming over to the Republican Party.