Click here for the latest coronavirus news, which the BDN has made free for the public. You can support our critical reporting on the coronavirus by purchasing a digital subscription or donating directly to the newsroom. A shift to mail voting is increasing the chances that Americans will not know the winner of November’s presidential race on election night, a scenario that is fueling worries about whether President Donald Trump will use the delay to sow doubts about the results. State election officials in some key battleground states have recently warned that it may take days to count what they expect will be a surge of ballots sent by mail out of concern for safety amid the pandemic.