I am not surprised by that. Despite the best efforts of the self-hating establishment (led by the likes of Barbra Streisand, Sandra Bernhard, and the Buchanan-loving kapo Robert Wexler [head of jewsforobama.org]), average American Jews are extremely uncomfortable with Obama's candidacy. Just a month or two ago, his support level among Jewry was only in the high fifties--a huge danger zone for a constituency that reliably goes 70-80% Democratic and has ever since they days of FDR--and now it's at 50/50.
I would not be surprised if Obongo loses the Jewish vote in November.