Hard to believe but -- sadly -- true. As Dennis Prager noted, many secular Jews continue to vote Democrat(ic) because they think they're voting for the policies of FDR.
That FDR thing is a bit of a lie, the Jewish vote was well left, well before FDR, it has always been so.
It was the black vote that switched for FDR, it totally reversed itself in 1936. Until and including 1932, the black vote was overwhelmingly Republican, and then it became overwhelmingly Democrat (and ever since), in 1936.