The worst thing to happen to a famous brand is not bad press but rather becoming irrelevant and falling out of discussion.
Even if the Trump political brand crashes and burns, the broader trump brand of success and money just gets stronger...
This election was the ultimate win win for Trump.
This is why he can take all the risks he is taking, he has nothing to lose...which is the ultimate trump card!
Edit: spelling correction
No doubt starting a cable network is a good fallback position, but I don't buy the idea that this is all according to plan.
More likely, some in his campaign know he's going to lose and are looking for an out, while others (maybe including the candidate) still think he may win.
His brand recognition is way up throughout the world and my experience tells me that the negative view will not translate into his business brands once his political brand is not front and center.
I've studied branding extensively and I think, if he loses, his presidential run will still be a net win for him and his brand once the political fallout falls out of the news cycle.
edit: changes nothing to little