You sincerely think that people don't know Bernie Sanders, from Brooklyn, who frequently cites his identity, is Jewish? Are you kidding me?
He's everything but a proud Jew, though -- every proud Jew is a Zionist. Sanders is as proud a Jew as Ana "Young Turk" Kasparian is a proud Armenian. I'm not exactly the only Jew viewing it this way.
Then the majority of American Jews are not "proud Jews", since just about all I've met don't really care at all either way about Zionism or Israel.
Uhm...
I assure you, many many Jews care deeply about Israel. Also, a huge majority of american Jews support a Palestinian state. Most polls of Jewish Americans also back up my point.
That being said, support for Israel =/= Zionism. They are not mutually exclusive.