Explainer-Why we may not know the winner of the US presidential election on Nov. 5

The U.S. presidential election will take place on Nov. 5, but the winner of the razor-thin race between Democrat Kamala Harris and Republican Donald Trump may not be known for days after the polls close. In 2020, some states experienced a "red mirage," in which Trump was leading on election night, before a "blue shift" saw Democrat Joe Biden overtake him, a phenomenon Trump used to amplify his false claims that the election was stolen. Democrats also have embraced mail voting more readily than R