“The American ones on the eastern coast seem to be culturally drawn to collectivist ideologies. Maybe someone here can explain why.”
There are a lot of theories. Mine is that historically, Jews were better accepted and more successful when they shed their religious behavior, particularly by non-Jews who were somewhat secular themselves. This was particularly true in the US. Leftism evolved from secularism, and Leftists have adopted a tribe mentality. Members of that tribe will defend it, irrationally, often against their natural self-interests.
But it's not against their own best interests.