For those of you who won't be triggered or have their eyes melt by reading tweets from a <GASP> UC-Berkely law professor, here is more detailed info:
https://twitter.com/Teri_Kanefield/status/1288829827806408704
Short answer: Constitution says the president's & vice-president's term ends on January 20, 2021, If no elections have been held by that point, Speaker of the House assumes role as president.
I.e., options are (1) hold the election or (2) welcome President Pelosi.
I.e., this is just more bluster.
I like this quote from that thread:
He invents a new crisis with the intention of sending everyone into a panic.
It works. Every single time. Predictably, people go into a panic spin.
Trump pushes your buttons and you respond.