Can we say that part (though certainly not all) of why people think Bernie is "authentic" is because he doesn't appear or sound polished, BUT:
Only a white man can get away with that.
- If a white woman yelled a lot, wore ill-fitting clothes and had unkempt hair, people would call her "crazy"
- If a black woman did that, people would call her "angry"
- And if a black man did that, people would call him "dangerous"
Hell, it can even become a positive meme for him: