To
understand what the 2017 exit polls are telling us in Virginia, it is first
necessary to understand what they got wrong in 2016. Estimates we have done for
our Voter Trends in 2016 project
indicate that Virginia's voters in 2016 were 38 percent white
noncollege and 32 percent white college. White noncollege voters supported
Trump by 67-27 and white college voters supported Clinton 51-42.
Compare this to the 2016 exits in Virginia. The exits claimed
that Virginia voters were 38 percent white college and just 29
percent white noncollege. They pegged the white noncollege vote at 71-24 Trump
but actually had Clinton losing the white college vote 45-49.
So, 2016 exit polls in VA practically reversed the correct
proportions of white college and noncollege voters. In 2016, there were still
more white noncollege than white college voters. Also, the 2016 exits
overestimated the white noncollege Republican advantage and didn't catch that
white college voters likely supported Clinton by a solid margin in the state.
OK, now to 2017. The 2017 Virginia exits claim that white
college educated voters vastly outnumbered white noncollege voters by 41-26.
They further claim that Northam carried the white college vote by a narrow
51-48 margin, while losing white noncollege voters by 26-72.
Extrapolating from the 2016 comparison above between exits and
our data, I'd say better estimates for VA in 2017 are as follows:
- White
noncollege and white college were likely close to equal as shares of
voters (perhaps around 35 percent each), not heavily weighted toward white
college as the exit polls claim.
- The
white noncollege margin for Gillespie was likely closer to 40 points than
46 points.
- Impressively
and significantly, white college graduates, judging from the shifts in the
exits between the two years and using our 2016 figures as a baseline, may
have given Northam a mid-teens advantage not the narrow 3 point margin
shown in the 2017 exits. That could be quite important going forward.
- As
for black voters, I am OK with the 2017 exits' estimate on margin (around
75 points) since our estimates and the exits agree on this data
point for 2016. Possibly black voter share is a bit overestimated by the 2017
exits, judging from previous patterns. I suspect, however, that the slight
decline in black voter share relative to 2016 registered by the exits is probably
real.
Why were the 2016 exit polls off? Wouldn’t that be important for estimating discrepancies in 2017?
ReplyDeleteLeo, the problem I alluded to is chronic with the exit polls. See the Appendix to our latest report, Voter Trends in 2016 (https://www.americanprogress.org/issues/democracy/reports/2017/11/01/441926/voter-trends-in-2016/) for a full explanation of why this is so and how we corrected the problem. And yes the same problem likely affected VA 2017 exit polls as well; my estimates for 2017 are a guess based on adjusting the 2017 exit poll results for the typical bias patterns shown historically by exit polls.
ReplyDelete