Trump should win in a canter. The incumbent leader in a crisis is a massive advantage. That's conventional wisdom.
Look at Australia. A few weeks ago Morrison’s approval rating was at 68%, while 27% of respondents were dissatisfied. His net approval rating was +41. However, in the FiveThirtyEight poll aggregate of around the same time, Donald Trump’s ratings with all polls were 40.5% approve, 55.5% disapprove (net -15.0%).
So Morrison judged competent, so a winner with voters at +41. Trump judged incompetent, so a loser with voters at -15. It seems Trump is in a world of pain with the voting public.
Don't count Trump out though.
The powerful corporations and global billionaires who have profited enormously from Trump, along with America's global enemies, have a vested interest in him getting a second term. Expect the mother of all smear campaigns against Biden, Attorney General Barr to corruptly use his office again for party political purposes in the lead up to voting, foreign social media disinformation campaigns, the closing of polling booths in Democrat and African American areas, African American sounding names struck off the electoral roll... You know, just the usual.
