https://www.washingtonpost.com/opinions/2020/11/19/why-were-polls-wrong-ignore-calls/
[emphasis added]
“To complete 1,510 interviews
over several weeks [for our 2020 Florida election tracking polls], we had to call 136,688 voters. In
hard-to-interview Florida, only 1 in 90-odd voters would speak with our
interviewers. Most calls to voters went unanswered or rolled over to answering
machines or voicemail, never to be interviewed despite multiple attempts.
“The final wave of polling, conducted Oct. 25-27 to complete 500
interviews, was the worst for cooperation. We could finish interviews with only
four-tenths of one percent from our
pool of potential respondents.”
…
“After the election, I noted wide variations in completion rates across different categories of voters, but nearly all were still too low for any actual randomness to be assumed or implied.”
