2016 had a voter-eligible participation rate of 56.9% – only fifty-seven of every hundred people eligible to vote (regardless of actual registration status) cast a ballot.
This is the lowest rate since 2000, which had a VEP rate of 55.3%. The highest rate since then was 62.2% in 2008.
Looking at the state results, and there appears to be a trend between the margin of victory and the VEP rate for that state – i.e. the “safer” a state is for a particular party, the lower the participation rate is likely to be.
For the five states with the lowest VEP, all but one had a margin above 25%. The average margin was 29.56. Those states were Hawaii, California, Utah, Tennessee, and West Virginia; all traditional “safe states”.
For the five states with the highest VEP, all but one had a margin under 3%. The average margin was 3.02. Those states were Iowa, Wisconsin, Maine, New Hampshire, and Minnesota; two classic “swing states” and several states which were considered toss-ups in RCP leading up to the election.
While the larger trend is clear on the chart, there is a lot of variance. A number of factors could be affecting this; ease/availability of early voting, voting culture, population demographics, etc.
Note: this post was originally written just after the election, so vote counts were not quite final in all states. Final numbers are just a bit different from the above.