I’m writing this now because I anticipate linking to it over and over again; this fallacy isn’t going anywhere.
Journalists have got very good at using the word “comparing” to turn the most innocuous statement into a gaffe, through a simple trick of equivocation. Most recently, Jeremy Corbyn is accused of “comparing” Israel and ISIS, but a search for “accused of comparing” finds many other examples. The pattern goes like this: a politician says something like “just as one doesn’t put a vampire in charge of a blood bank, one shouldn’t put the press in charge of protecting privacy”. This use of analogy is one sense of the word comparing. However, many now seem persuaded that “comparing” really means “equating”. Thus we start with someone using a vivid analogy to make a point like “you should consider someone’s partisan motivations before giving them an important responsibility” and through the magic of this word, this becomes “Politician claims Rupert Murdoch kills people and drinks their blood”, which as far as I know he doesn’t.
I’m even less of a fan of Dan Quayle than of Jeremy Corbyn, but he too fell foul of something very similar, though the word itself wasn’t used. In the 1988 vice-presidential debates, he used the example of JFK to argue that a short Congressional service need not be a bar to high office. Lloyd Bentsen replied with the now-famous put-down “Senator, I served with Jack Kennedy. I knew Jack Kennedy. Jack Kennedy was a friend of mine. Senator, you’re no Jack Kennedy.” Of course Quayle was claiming no such thing; he was simply showing that the charge against him proved too much. But this deliberate misunderstanding is one of the most celebrated lines in VP debates.
The thing that’s most annoying about this is that it’s natural to reach for the most extreme example to prove your point. If we oppose vigilante justice even for murder, we certainly oppose it for littering. If we should defend the right to free speech even of Nazis, we should certainly defend it when it comes to, say, Tories. If we’re not going to hold all Saudis responsible for Osama bin Laden, we’re certainly not going to hold all Canadians responsible for Justin Bieber. To me this seems like a normal move in argument, but if I were a politician I couldn’t say any of these things, for fear of being accused of “comparing” Bieber to OBL.