Okay, well firstly I thought you were deliberately saying stupid shit to entice a reaction, hence accusing you of trolling.
But perhaps you're not. Perhaps you're stupid enough to think that Chelsea fans who have supported the club since before Abramovich would just say "right, they're Jewish now, we're off".
To answer the above quote, probably not. There probably is a certain level of anti-semitism under the surface, and when you have a manager performing badly, who happens to be Jewish, perhaps some forget to keep the anti-semitism down out of anger, and it comes out. It happens, it's human nature. I can guarantee you though that had Avram Grant been a really good manager, no-one worth their salt would even think about his religion. I can also say that this trait is not English, it's human.
Where was I going with this? Where are you going with this?