[MinorityRepublican]

I saw a slightly extended, wider angle clip that showed there were chairs behind the VIPs. He was trying to sit down ahead of schedule.

Seems the likely explanation here. He's senile.

Plus I bet Joe's handlers told him no ice cream until the event is over.

[ProtectOurFreedom]

“He’s senile.”

Yep. He starts to sit down, then thinks to himself “I wonder if there’s a chair under me?” Oops, no chair and he stops in the half-way down position. How pitiful is that?