Just because the media has slandered him as a Nazi does not make him so. Just like calling Bernie a Communist does not make him one.
for that comparison to make any sense, there would be the need for....
1) a lively communist or even stalinist youth scene inside the US.....
2) creating their own online universe on popular places like 4chan and spreading their thoughts successfully
3) becoming more influential through co-opting an existing high-traffic website, which gets even bigger and more influential through doubling down on the stalinist thingie.
4) that website would be run by Bernie Sanders who fostered those stalinists and made way for ideologial more pure people than himself.
i am not saying that Bannon is a Nazi - i am saying he is not too much disturbed by parts of the Nazi agenda and has no problems at all making big bucks with Nazis and creating a safe space for them.