Except for Florida, the national Jewish vote is concentrated in heavily Democratic states that will vote for Obama no matter what.
I think Obama’s sudden pro-Israel charm offensive is aimed at white Evangelicals, who voted about 30% for Obama in 2008.
Evangelical political support for Israel is passionate.
In states like Georgia, North Carolina, Virginia, Ohio, Indiana, and Iowa, Evangelicals could swing the vote for or against Obama.
And, of course, this will not matter in NY or CA (since, as you say those stated will go barama anyway), but could be VERY important in FL, PA, OH and MI.