One of the things that struck me in the original footage of the ‘confrontation’ was that Joe was actually ‘confronting’ Obama - looking straight into his eyes, hands on his hips - iow, he didn’t flinch, like Obama’s typically white grandmother (RIP). And I think that is what got under Obama’s (and his supporters’) skin.
Joe treated him like just another mortal and he wasn’t used to that! :-)
That is a great observation.