I thought this was an interesting and pithy comment by imnobody00, replying to the question posed in this post.
It’s easy. Leftist Jews are secular/reform Jews. When they came to the West, they had two options: to remain in a secluded community or to integrate. Since they were secular, they wanted to integrate. They could integrate by adopting Christianity, but this was the enemy of their forefathers, a kind of ancient taboo.
Or they could integrate by adopting the religion of the Left, which filled the religious void they had in their minds, integrated them to the West and wasn’t a taboo or a historical enemy. In addition, it was the religion of brainy people, such as them. They did that although retaining their ethnicity. Since the religion of the Left, it is anti-Christian and anti-White, they are anti-Christian and anti-White. They have a plus because they are Jews so they remember grievances against Christians.
In short, the Jews that are producing these mayhems are not Orthodox Jews but converts. Converts to the religion of the Left. Their Judaism is vestigial and disappearing, when they intermarry (think Woody Allen’s kids) or have a low birthrate. This is why Orthodox Jews will be the majority of the American Jews in some few decades.
I would only demur that from what I’ve read and heard plenty of Conservative Jews are equally as leftist as their secular/Reform brethren. So apparently choosing the lower-integration path doesn’t also thwart the desire to adopt Leftism as a supplementary religion. My follow-up question: are Orthodox Jews in the U.S. against open borders and multikult in meaningful numbers? There are enough of them that a breakdown of their voting preferences shouldn’t be hard to determine. If they are, that would lend credence to imnobody00’s argument that Leftism is only a religion for otherwise irreligious Jews seeking a substitute to fill their spiritual void that isn’t Christianity.