He did go too far. He shouldn't have accused Fox of faking his symptoms. And he shouldn't have mimicked them on camera, no matter what his reasoning for doing so was. If Rush had just stuck to addressing Fox's argument, there might have been a chance that Fox could have been exposed. But no - Rush ended up comfounding the real arguments that could have been brought up by bringing this extraneous crap in. And what happened? Rush's mimicry and wrong quotes about Fox were widely distributed. Fox got to make himself look good by saying that Rush didn't understand his illness. But Fox never had to respond to the factual errors in his ad. Why? Because Rush managed to create a bigger, bogus issue that overshadowed the original content of the ad.