Bit idea

At a rally Trump starts with a complaint.

"A radical left Marxist Youtube video Trump. Made fun of Trump. Many hours minutes long. Very long. It was wrong. Very wrong. Redub now."

Rebut? Probably. And he proceeds to speak near gibberish in a six hour jeremiad on sharks, toilets, "windmills" and many of his other greatest hits. At his lowest point he rants angrily for ~30 minutes on "new tv fried chicken" and how "old was better but not better". He gets so worked up - he doesn't say a single additional word about the video or even Marxism itself.

We spend hours looking for the video with no luck. Finally somebody says that maybe Trump's broken brain made the whole thing up.