Is post-election violence impossible in 2020 America? No.

However, data suggests it is unlikely.

Ninety-five percent of the 12,607 political demonstrations in the U.S. between May 24 and Sept. 19, 2020, were peaceful. There were 351 other kinds of incidents, including imposing curfews and perpetrating physical attacks. In 29 of those, there was violence against civilians, where 12 people were killed, nine of them by the police.

https://acleddata.com/2020/09/03/demonstrations-political-violence-in-america-new-data-for-summer-2020/

And

https://acleddata.com/2020/07/09/introducing-the-us-crisis-monitor/