I think not.
If there's one facet of humanity still functioning in the semi-sentient blob of protoplasm called Donald Trump, it's the instinct for self-preservation.
The next Dem nominee is not going to get shocked into submission by him gooning over their shoulder in a debate, is not going to be shouted into silence by his screams of "NO PUPPET NO PUPPET, YOU'RE THE PUPPET!" and isn't going to hesitate to produce facts and sources to forcibly call him a liar in real time. This time Trump has a voluminous track record of corruption, broken empty promises and outright fuckups to throw in his face, and I'm pretty sure that even in the depth of his delusion, his survival instinct will warn him of the danger of facing even the weakest possible Dem candidate in a one-on-one environment with no Hannity, Limbaugh or McTurtle to protect him.
I expect he will publicly deem debates to be beneath him, because "everybody knows that ____________ is a lying commie and debates are rigged blah blah blah" and therefore decline to participate, setting a new shining example for incumbent presidents, to the cheers of his 22% base.
What do y'all think?