What are the factors contributing to the sense among experts that this election is taking place under unusually volatile conditions

Fewer than half of Democrats (46%) were even somewhat confident in an accurate and fair election, compared with 75% of Republicans. And Democrats were deeply concerned over whether all citizens would be able to vote: Just 43% of Democrats said they were very or somewhat confident all citizens who want to vote would be able to do so, while about twice as many Republicans (87%) were confident all citizens would be able to vote if they wanted to.

Multiplying frequency by period