
Or another possibility: 4D chess (Public Board)
It is conceivable that the very weak reason for the mistrial was concocted in order to ditch the verdict.
It is possible that the Dems are saying "this is turning everyone against us, let's lose this verdict and act like it didn't happen."
A mistrial would be an explainable technical reason for abandoning the verdict against Trump while saving face.
We'll know soon enough.