American Jews don't seem to be as supportive of Israel as they once were. As many have said, many of them are liberals first and Jews second, at least among the more secular Jews. And liberals in the US often tend to look for the groups that seems most to be a victim (whether or not they actually are), so many libs are now siding with the 'Palestinians'.
It's a strange development that will probably receive more and more attention in the future.
What is even more bizarre is that American Jews living in Israel voted for McCain/Palin over Obama/Biden by a 3 to 1 margin.