I share your concern, but I don't think it's just about Trump's celebrity per se (though that was a necessary precondiiton for his success), it's more about his individual style that draws people to him.
Despite the fact he's the most dishonest politician in living memory, his laid-back confidence and willingness to say the outrageous and "politically incorrect" thing in a humorous, off-kilter way makes him very convincing to many people. He's an expert conman, which is why he's been able to pull off so many scams and live off his name for so long.
For me, this is somewhat reassuring because it means there won't be another Donald Trump anytime soon - it's not like any old Republican can now come along spouting the same vapid slogans and try to copy the essence of Trumpism - they need Trump's personality to pull the scam off.
This is why I'm not too concerned about Don Jr or any of the other brats running - they aren't their dad and never will be.
