I have many Jewish family members, and ALL of them are Republicans.
I have many Jewish in-laws, too, and ALL of them are Democrats.
The differnece? My family has been in Texas for a long, long time, and are generally Sephardic and deeply religious.
My in-laws are not deeply religious --- indeed secular -- and are largely intermarried (indeed, my wife's mother is a nominal convert post-birth, making my wife a gentile), and are all urban dwellers --- LA, Houston, New York.
The last statistic i saw was that 85% of Jews voted Democrat.
I am your counterexample: An urban-dwelling (NYC!) Ashkenazi Jew who is Republican. ;)
The dispositive variable, in my experience, is age. Pre-war New York City Jews are not unlike pre-war New York City buildings.