2020 House · IA-1
Monmouth University Polling Institute · fieldwork ended 2020-10-17 (17 days before the election) · 352 respondents · Live Phone/Online Panel
The poll said
Democrat 56% · Republican 42%
D+14.0
The certified result
Democrat 48.65% · Republican 51.24%
R+2.6
The arithmetic
- Poll margin = 56 − 42 = 14.00
- Actual margin = 48.650 − 51.245 = -2.595
- Signed miss = 14.00 − (-2.595) = 16.595
- Absolute miss = |16.595| = 16.595
The poll overstated the Democrat by 16.6 points and had the wrong leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 71671, race ID 7988 (538 database).