Midterm Polls Show Democrats Up 8 Points as Analysts Warn Republicans May Be Underestimated
Updated
Updated · The Washington Post · Oct 8
Midterm Polls Show Democrats Up 8 Points as Analysts Warn Republicans May Be Underestimated
3 articles · Updated · The Washington Post · Oct 8
Summary
Democrats hold an roughly 8-point national House lead and narrow Senate advantages in six GOP-held races, but analysts say those margins could still mask stronger Republican support.
Recent polling misses fuel that concern: surveys at this stage from 2018 to 2024 overstated Democratic Senate support by 6.2 points on average in Iowa, Michigan and Ohio, while 2020 polls missed by 4.7 points nationally.
Nonresponse bias has been the main culprit, with Trump-aligned voters—often less engaged, less trusting and harder to reach—participating at lower rates than Democrats.
Pollsters have responded by using voter-file samples and weighting for education, party, turnout and past presidential vote; one Washington Post review found past-vote weighting cut bias by 1.6 points on average.
Even with those fixes, the outlook remains uncertain: a 3-point Democratic overestimate would likely still leave Democrats winning the House but losing the Senate, while a 3-point Republican overestimate could produce a Democratic wave.