6 June 2016
Montana voter turnout 1920 – 2016
Voter turnout can be measured several ways, but the most common measures are the percentage of Registered Voters who vote, and the percentage of the Voting Eligible Population that votes. Registered voters is a subset of the VEP, which is a subset of the Voting Age Population (age 18+). Montana’s Secretary of State maintains a list of historical registered turnout, but not of VEP. Fortunately, VEP data are available from the U.S. Elections Project.
Unfortunately, VEP is a statewide statistic that’s not available for counties. But, there’s a workaround. In Montana, the VEP is approximately 98 percent of the VAP for 1972–2014. In the state’s largest counties (Yellowstone, Missoula, Gallatin, Flathead, Cascade, Lewis and Clark, and Silver Bow), the VEP can be estimated from the VAP.
Registered voter turnout is best used for elections administration. For two reasons, VEP turnout is the best measure for elections policy. First, voter registrations lists contain deadwood, voters who are no longer active but cannot be removed from the list legally. In 2000, for example, Montana’s number of registered voters exceeded the VEPO. Second, not all who are eligible to vote register. Imagine there is a Corncob County, with a VAP of 110,000, a VEP of 100,000 and 10,000 registered voters. If 9,000 corncobbers vote, the registered voter turnout is 90 percent — but the VEP turnout is only nine percent.
Flathead Memo’s Montana Turnout 1920–2016 spreadsheet contains two sets of VAP. One covers 1948–1970, when 21 was the minimum voting age. The other covers 1972–present, for which 18 is the minimum voting age. The spreadsheet’s VEP set covers 1972–present.