should Democrats stop thinking of Wisconsin as a rust belt state?

[Pericles]

Feingold lost to Johnson by a higher margin than Clinton lost to Trump.

I would assume from this that Wisconsin is becoming more establishment friendly, and more pro free trade than neighboring Michigan.

As much as it pains me to say this, I have to conclude Bernie Sanders would struggle to swim against the current in this state.

No, Feingold was seen as too much of a hollow entitled establishment.

And Clinton wasn't also seen as that?

I suppose you could attribute it to Ron Johnson being more popular than Trump but still.