Trump Mocks Joe Biden For 'Listening To The Scientists' | Morning Joe | ...

Trump is not campaigning for office because he cannot campaign for office.  All he is doing is; entertaining the people who show up, thinking they're Trump supporters. First of all, Trump has run political professionals away, all he has left are hangers-on who do not know the craft.  Meanwhile, his audience is not made up of supporters. 

If they were supporters they'd insist that he became more mainstream and tried to widen his appeal.  After all, no one want to see their candidate lose, but these people simply don't care, they're there solely for the entertainment function which gives them a place to go and people to consort with for a while.