Just a random thought, but why are the majority of Jews in our country still ID-ing themselves as liberal and democrat?
Some are just very liberal, but for many it's very difficult to break their loyalty to the party them welcomed them when they first emigrated to America is large numbers. The Republican Party, made them feel very unwelcome in the old days. The Democratic Party welcomed the millions of immigrants like the Jews, the Irish, the Italians, and a number of other European immigrants. The Republicans were the ones trying to keep immigrants in their place.
Not even the fact that the KKK hated both Jews and Republicans convinced many Jews to join the GOP.
Times change. While there is still a small segment of anti-Semites on the right and cheerleaders for the anti-Semites like Pat Buchanan, the GOP is not the same anti-Jew party it was in the days of yore.
But still before the modern era many Jews identified with civil rights that they felt were best championed by the Democratic Party. This despite the Solid South being anti-black and anti-Jew.
There is also the fact that many Jewish women are very strong proponents of abortion which the Dem Party also strongly supports and the Republican Party opposes.
We'll see how this all shakes out next year. Anti-Jewish sentiment has been growing in the Dem Party as shown in recent polls.