In Arizona, where the vast majority of voters cast ballots by mail and which allows for mail-in voting or for voters to drop off mail-in ballots at polling places, the count has taken longer. Sinema did not pull ahead of Republican Rep. Martha McSally until Thursday.
As of this writing, only 83% of the Arizona vote is expected to be in.
In California, where absentee voting is open to all voters, mail-in ballots must be postmarked by Election Day and received within three days of Election Day. Officials speculated before Election Day that it would take weeks to count all the ballots. That late vote has helped Democrats pull ahead in several House races.
Recalling 2016, this vote lag is how Hillary Clinton continued to grow her popular vote lead over Trump long after it was clear on Election Day that she had lost the Electoral College and thus the election.