Arizona was predicted to be the swing state most prepared to manage the onslaught of mail-in ballots. In 2018, 79% of Arizonans voted by mail. This may account for why Arizona was historically slow to report vote counts.
But in 2020, Arizona was amongst the first states to be called for Joe Biden. With only 73% of the state’s votes counted, Fox News projected that Biden would win Arizona’s 11 electoral votes. At the time, more than 900,000 votes were still to be counted. Most of them were from election day in Maricopa County where 60% of the electorate lives.
When 99% of the votes had ultimately been counted, Joe Biden’s lead over Donald Trump was only 10,000 votes or just .3 percentage points.