This is an interesting article.

This story…hoo boy 😬 https://t.co/CciFck9cJe pic.twitter.com/RIpuq9uA2o

— Asha Rangappa (@AshaRangappa_) November 29, 2020

Advisers and allies, including Senate Majority Leader Mitch McConnell (R-Ky.), encouraged Trump to try to close the gap in mail-in voting, arguing that he would need some of his voters, primarily seniors, to vote early by mail. But Trump instead exhorted his supporters not to vote by mail, claiming they could not trust that their ballots would be counted.
“It was sort of insane,” the former campaign official said.
Ultimately, it was the late count of mail-in ballots that erased Trump’s early leads in Georgia, Pennsylvania, Wisconsin and other battleground states and propelled Biden to victory. As Trump watched his margins shrink and then reverse, he became enraged, and he saw a conspiracy at play.