Goldberg himself might not have had anything to do with the (and Al Franken is number 37) part. The editor might have done it to sell more books.
Something similar occurred with John Stossel's book "Give Me A Break". That's the title of the book. But then, this was added (How I Exposed Hucksters, Cheats, and Scam Artists and Became the Scourge of the Liberal Media). That's just to sell books. If you read Stossel's book, he is still faithfully libertarian and doesn't change his views just to please conservatives.
The same with Goldberg. He includes well-known conservatives in his list of people negatively influencing America. I know Judge Roy Moore is on the list, along with others. Please don't judge the book by it's cover :-). You're right, the line in parentheses is a pander, but the actual book itself represents his actual views.
Regarding John Stossel's book, it's a shame that the very stupid-sounding subtitle was tacked on by the editors.