Skip to content

2012 Senate · MT

Mason-Dixon Polling & Strategy · fieldwork ended 2012-10-30 (7 days before the election) · 679 respondents · Live Phone

The poll said

Democrat 45% · Republican 49%

R+4.0

The certified result

Democrat 48.58% · Republican 44.86%

D+3.7

The arithmetic

  1. Poll margin = 45 − 49 = -4.00
  2. Actual margin = 48.578 − 44.860 = 3.718
  3. Signed miss = -4.00 − (3.718) = -7.718
  4. Absolute miss = |-7.718| = 7.718

The poll overstated the Republican by 7.7 points and had the wrong leader.

Where these numbers come from

Poll and result: 538 raw_polls.csv. Poll ID 51340, race ID 1487 (538 database).