My husband's Jewish (I'm a convert), but his dad was a total McGovern supporter back in the day, and etc. Still, their people came over a bit earlier, the patriarch of the Russian branch got out in the back of a hay wagon after the 1905 revolution, and the Austria-Poland contingent not much later. So while they dealt with the typical American anti-Semitism, especially as in those days, there were no specific ties to relatives in Europe during WWII (although most--all?--of the young men of age served in the US military during the war). I wonder if that earlier immigration date makes a difference.

The larger extended family on both sides has a range of observance vs. assimilation. Overall those whose political leanings I know are center to left.