Yes I agree, Sanders would certainly have been a candidate of change. I saw comparisons with The Sun vs. Neil Kinnock, particularly in 1992 which was the only election in which it appeared credible that Labour might have won under him, only on a far more vicious scale against Sanders. The portrayal would have been that he would be disastrous for the economy at a time when Trump was offering jobs for all and immigrants out.
I would certainly have been interesting to see how Sanders would have done, but I wouldn't underestimate the visceral contempt that exists in the American media and even mainstream society for anything that is termed Socialism/"The Left".
It has subsequently been woven into the whole political discourse since McCarthyism and The Cold War and you could argue that distrust/suspicion of socialism and socialists is ingrained in popular culture in The USA.
Both Trump and Sanders would have been anti-establishment candidates, only Trump is more socially anti-establishment and Sanders economically. There would have been significant ammunition for the Trump campaign and he would have found himself aided and abetted by large sections of the media too.