Maybe former Commentary editor Norman Podhoretz was right when he wrote after the 2008 election that no matter how dire the situation for Israel, Jews simply cannot bring themselves to vote for Republicans. As much as American Jews care, or claim to care, about the Jewish state, they are not one-issue voters. They care just as much, if not more, about issues that other liberal voters care about, like abortion and gay rights. (Podhoretz had hoped for “buyer’s remorse” among Jews who supported Obama in 2008, but no such luck. The latest Gallup poll shows that Jewish voters are going for Obama over Mitt Romney 70 to 25.)

There’s also the fact that the voting habits of Jews, like everyone other American who has ever stepped into a polling booth, are dictated as much by emotion and tradition as by reason. If you imagine your immigrant grandparents are watching you, it’s a lot harder to pull the lever for the guy with the million-dollar country-club grin. Some will argue that this is what’s going on with Dershowitz, Koch, and Saban.

The strictly political interpretation of their apparent flip-flop is that it allows them to be kingmakers of a sort. Koch has crossed party lines before: He backed George W. Bush for re-election in 2004, and his support for Bob Turner when he was running to replace Anthony Weiner in New York’s ninth district might have helped put the Republican over the top. But if Koch did nothing but cross party lines, he’d make himself irrelevant within the party. Remaining a Democrat while criticizing the president makes him an unpredictable player that top Democratic officials have to keep happy.