I find it interesting that all someone has to do is google "Robert Byrd" "hermann goering" and "losing america" and they find all sorts of information about it.
To indulge: Chapter 8 of his book begins with a long quotation from Goering and links Bush's justification of the Iraq war to this quote, meaning that Bush is using Nazi tactics to justify the war. Does Byrd say "Bush is a nazi."? No. But I suppose if someone used quotes from Hitler and said "Obama sounds just like that" it might be interpretted in a bad light.
I cannot post a link to the exact page of the book. Most likely due to copywrite it isn't available. What I am referencing is
this, a review of the book. If you do not trust it, I suggest you look at the 100s of other links out there pointing to the same information.
I honestly do NOT find any benefit in trying to define which comparisons to nazis are worse than others. JW basically said "oh yeah? well that's just not as bad". I don't see the reason to continue that portion of the conversation.