I don't agree with the statements made in the ad. That's where Rush would have been effective. Had he simply pointed that out instead of waltzing into the politics of destruction, he would have been fine. BTW, I've always enjoyed your scenery photography.
Fox singled out a candidate and said he was against research to cure diseases and his election would destroy the hope of "people like me" -- meaning himself. The "people like me" reference was illustrated by his palsy movements onscreen as he talked.
That is how Fox made it personal, and a response on a personal level is appropriate.
Rush did not mock him or the disease. Rush explained the message and debunked it.
He also did something important by questioning the extent of the effects of Fox's disease and the control that can be attained through meds available now. Is Fox really without hope, or just without meds he likes to take? Let's understand the disease and the current treatments, and to do that we must ask questions.