“evidence that Chauvin can point to in order to establish that his right to an impartial jury was denied.”
Absolutely!
He [Chauvin] can do or say whatever he pleases. The “verdict” will stand. This trial was political, not legal. It was the same as Hitler putting a Jew on trial before a “People’s Court” Or Stalin putting someone on trial by a “Special Tribunal” The verdict and sentence of the defendants were foreseen and foreordained. Guilty and death.