It‘s not Election Day, November 3, 2020 you need to look to, but instead it’s Inauguration Day, January, 20, 2021.
If Trump (and the GOP majority in the Senate) loses on November 3rd, but say on Nov 5th RBG dies in the SCOTUS, Trump can push through her replacement before he’s walked out of office on January 20, 2021.
When Trump loses he has almost two months to rage on insanely, calling for his supporters to challenge the bogus election, etc. That period between Nov 3rd and Jan 20th is going to be one of the darkest periods of America‘s postwar history.