Public speaking/debate is not the Presidents strong hand, most if not all folks that lean right already know this and will blow off any failings he may have in that area. Sure, I wish he was better in that area but we have to run with what we have.
The debate format is not his friend for sure. Put the two of them at either end of a table, no time limits, no moderator to interrupt, and Joes head would explode in 5 minutes.
Board room debates are an entirely different animal. And how schit gets done in business.
