the world knows it, even Bernie knows it.
And while I might not vote for Trump, many other Jewish voters might; Bernie's socialism not only threatens their economic success they've earned over generations, but his unpopularity among Jews (given the D-primary) would give Trump an opening, he'd counter the Duke allegations of the world with Bernie's anti-Israel fans, and could put a Jew on his ticket. They'd not only gain on the Jewish vote, but they'd get a lot of campaign donations and political participation to boot. Jewish voter turnout is WAY higher than the youngsters who go vote for Bernie. America is capitalist; campaign donations matter. Plus, Trump would not only have his own money, but Wall Street money which Bernie eschews because all money is evil to him.
You do realize that in Europe, the formerly left-voting Jewish populations now all vote right? They did that because of obsessive and conspiratorial anti-Zionism and softness/accomodation to Islamist ideas. That could happen here with Bernie.