In fact it is very possible that some Jews had supported Hitler, ysh"v. They didn't know what he was going to do. He only proposed to quit them German citizenship and consider them foreigners. At that time it might have sounded an attractive idea... If Jews were not Germans..then they are a Nation and had to be given their Land in Israel.
And the Jews who voted for Obama.... excuse me if someone if hurt.... but Christian Fundamentalists did it. Specially Reform Jews, even if secular and very little religious, are worried about Christian Zionism taking power in America, they fear it will blurr the line between Judaism and Chsritianity. Regarding the danger of assimilation, they have a point. I'm also worried about that, but I wouldn't have gone so far as to vote for a Jew-hater.