Oct. 23, 2020, 9 a.m., with 10 days before the election, Fox New releases a poll showing President Trump trailing Joe Biden by eight percentage points.

Oct. 23, 2020, 3 p.m., at a hastily convened news conference, President Trump announces that the Food and Drug Administration has just issued an Emergency Use Authorization for a coronavirus vaccine. Mr. Trump declares victory over Covid-19, demands that all businesses reopen immediately and predicts a rapid economic recovery.

Given how this president has behaved, this incredibly dangerous scenario is not far-fetched. In a desperate search for a political boost, he could release a coronavirus vaccine before it had been thoroughly tested and shown to be safe and effective.