I recently read Michael Moore's autobiography "Here comes trouble". In it he tells what happened after he movie "Fahrenheit 9/11" came out. Republican spin doctors studied its effect and found that it had considerable influence on how people thought about Bush and how they planned to vote in the next presidential elections. So they decided that the only thing that would work was to blacken the image or Moore and his movie so much that no well-thinking Republican would even think about going to see it. They did this with quite some success.
Of course this is not the first time such a strategy is used. One can still find some old Republicans who can get red hot about Roosevelt's New Deal. And more recently the same strategy has been employed against Obamacare.