Over at the Jerusalem Post, blogger Shmuel Rosner has a provocative analysis of last week’s Gallup Poll, which shows that support for Israel is at a 19 year high among the American public – but which also a widening gap between Democrats and Republicans on the issue.

He writes: “As far as I can recall another record was set in this poll: the gap between Republican and Democratic support is higher than ever (37 percent!). Two years ago, I wrote about another poll in which the difference was “significant”: it was a mere 20 percent.”

Jewish Republicans say that points to a likely partisan shift in their direction among Jewish voters, which sounds a lot like wishful thinking, given recent elections; Jewish Democrats dismiss the numbers as meaningless, which sounds like whistling past the graveyard.

I’m guessing the analysis is a little more complicated than either side admits.

Far more Jews identify as Democrats than as Republicans. In most – but not all – elections, the growing independent Jewish vote still trends heavily Democratic.

And the argument that the Republicans are stronger supporters of Israel than the Democrats, and so Jews will start crossing the line en masse,  has been around for years – and yet Jews tend to stick to the Democrats.

What gives? Seems to me there are only two reasonable explanations.

The first is that, as the Republicans say, Jews will gradually move over to their column as the Democratic party becomes less friendly toward Israel.  These kinds of numbers are just leading indicators of a change that is already taking place, albeit slowly, they argue.

Maybe.  But it’s also possible something else is going on: rank-and-file Jewish voters know Republicans tend to be more hardline supporters of Israel, or at least of current Israeli policy, and they don’t much care.

Maybe because that’s because a lot of American Jews don’t like current Israeli policy, either.

Or it’s because Israel just isn’t a big factor in their political decision making.

Talk to a a random sample of Jewish leaders, and in private, at least, most will lament what they say is a growing detachment from Israel among American Jews, especially younger ones.

Maybe the Democrats aren’t as gung-ho about Israel, or at least the current Israeli government, but nobody’s saying Israel’s aid should be cut off,  a Democratic president isn’t pounding Israel with a diplomatic sledgehammer, so what’s the big deal?  Where’s the crisis?

Absent a crisis, maybe the growing gap in attitudes about Israel just isn’t much of a factor to many Jewish voters.

Maybe the widening gap between Democrats and Republicans when it comes to support for Israel, combined with the continuing Democratic voting behavior of most Jews, reflects something that spells bigger trouble for Israel: most American Jews just aren’t that involved in the issue. Mirroring the widening gap between Democrats and Republicans on Israel is the widening gap between pro-Israel activists in the Jewish community, a relatively small minority,  and rank-and-file Jews who care about Israel, but don’t make it their highest priority.

If I was a Jewish Democratic leader, I’d be worried; there’s no way to spin theser numbers as good for their side. If I was the leader of a single-issue pro-Israel group, I’d be a lot more worried.