Novelty value only, he has no chance of being elected
I remember people saying something similar about Dubya during the primaries.
Trouble is that in the American heartlands his bluff ‘straight talking’ persona plays well and there is an intense dislike of a (largely imagined by Fox News)) elite of effete, metropolitan liberals.
As a result, the gleeful mocking of Trump by various comedians and the twitterati actually plays very well for him amongst the conservative base who love anyone that leaves the ‘Liberal Elite’ fizzing with incredulous outrage.
That said, John Stewart nails it, as per usual.