Never. We will never join the xenophobic, racist party, having been victims of that stuff so many times.
Jews are becoming Republican slowly. If the GOP dropped their religious fundamentalist stance, more Jews would become Republicans, as many of the Jews I know are socially moderate to liberal, but conservative in economics. On the other hand, Jews are represented in disproportionate numbers to their numbers in the general population in the fields of law and education, and two of the GOP's top targets are trial lawyers and teacher unions, so many Jews have their economic livelihoods at least somewhat tied up with the Democratic Party.
I would not be surprised if Jews, as a group, become split-ticket voters; more Republican for President, but Democratic in down-ballot races.