Just throwing this out there.

He still believes he won the election and is the real president. Still, illegally, uses the presidential seal on his speaking podiums at private functions.

When my father-in-law's dementia was worsening, we were advised to give him stuff to do like he was back at his old job. The example we were given at a in patient facility, was they would give former nurses and doctors a chart and have them do rounds with the other patients. So when he was "sundowning" in the afternoons, he always wanted to call his broker, or his banker, or someone down at the chemical plant he ran but sold forty years before. We'd give him old contracts to mark up and review. Often calmed him down. So, I could almost see family and staff doing something similar? It was interesting, that even late in the progression he could still multiply big numbers in his head and he knew all the back roads to his old plant. There were times he was quite lucid and times he did not even know where he was. It's scary stuff.