That's an age gap that has been widening since it first began to emerge in the early 2000s, and it raises an important question: Just who actually comprised the 2016 electorate? What we still don't know on this most basic of questions -- or more precisely, what we think to be true that's actually wrong -- is fundamentally important to our efforts to improve the participation of one demographic group in particular: younger Americans.
Consider, for example, the median age of November's voters -- the value at which 50 percent of the ballot-casters were younger and half were older. Some basic extrapolation with the national exit-poll data quickly reveals the answer: 47.5. This sounds reasonable enough on its face - and maybe even a bit old. But now consider this. The median age of all eligible voters in the U.S., based on the most recent Census Bureau survey, in 2014, is also about 47.5. Thus, it follows from the 2016 exit polls that the median age of those who didn't vote in 2016 - a full 40 percent of the eligible population - would be roughly the same.
This is absurd on the face of it. It's also a repeat of the big miss the exit polls made in 2012, when the median voter age was pegged at 47. In its post-election survey published in 2013, the Census Bureau found the actual median voter age to be 51.
Census survey data won't be available for the 2016 contest until this summer. But the 60 percent turnout of eligible citizens was almost identical to 2012's 59 percent. Meanwhile, since 2012, America's voting-age population has grown about a year older. The median voter age for 2016 was probably closer to 52. From there it's simple math: The median age of those who stayed home would be about 41.
These discrepancies may sound trivial or even inconsequential. But they are actually a remarkably big deal. Fail to understand this most basic of questions -- who actually votes in our elections? -- and we'll likely continue making the same mistakes in our efforts to engage and activate more voters.
Fortunately, there's one particular type of American election where we now have a far better grasp of this question. This October, a team of us at Portland State University published a study titled simply "Who Votes for Mayor?" Funded with a grant from the John S. and James L. Knight Foundation, the study looked at the most recent mayoral elections in 50 cities, including the nation's 30 largest.
No exit polls exist for these elections. Most are held in odd-numbered years, and eligible-voter turnout is typically just 15 to 25 percent. For our study we obtained 22 million voting records, then painstakingly geocoded them on a map along with a wide range of census-tract data.
Few states' voting records contain information about race and ethnicity, and none have data about income, education level, marital status or a host of other demographic factors that make exit polls so fun to read. But there is one metric that almost every voter-registration record does contain: age.
As a result, our study was able to draw some rock-solid -- and remarkably stark -- conclusions. In a typical large city, the median age of citizens is five to six years younger than the national average, at about 42. But the median age of those voting in mayoral elections is 57, nearly a full generation older. The highest median voter ages were found in Las Vegas (68), Miami (68), Fort Worth (66), San Antonio (63) and Dallas (62).
The odds that an older citizen was a voter rather than a non-voter, compared to those in the younger cohort, averaged 7 to 1. In a few cities, the relative electoral clout of residents 65 and older was far higher - ranging as high as Fort Worth's 56 to 1.
We see much the same dynamic in the non-presidential midterm elections, in which all 435 member of the U.S. House and more than 6,000 of the nation's 7,300 state legislators are chosen. While the 2014 exit polls pegged the median voter age at about 52, research we've done shows that number closer to 57.
What does this all mean for our democracy and the choices we make? What happened here last Nov. 8 bears an eerie similarity to what happened in Great Britain on June 23, with the close vote in favor of exiting the European Union. More than 80 percent of British voters 65 and older cast a ballot then, while fewer than 50 percent of those between the ages of 18 and 34 did. One despairing young English voter tweeted just after that election that he was "truly gutted that our grandparents have effectively decided that they hate foreigners more than they love us and our futures."
While many younger Americans expressed similarly bleak morning-after sentiments on Nov. 9, the same rejoinder applies: The older generation overwhelmingly showed up to vote; most younger citizens simply didn't. If younger Americans know what they want - or don't want - it's a lesson they need to remember. So do the parties and candidates whose sentiments they share.
