Nearly three-quarters of Iowans who cast ballots in the June 5 primary were at least 50 years old, while only 12 percent were under age 35, a statewide statistical report shows.

Seven in ten Iowa Democratic primary voters this year were over age 50, while only one in seven who cast ballots were under 35.

Several well-funded Democratic candidates for governor or Congress devoted resources to engaging younger voters this year, which helped bring more millennials to the polls. But because turnout was high for all age groups compared to the party’s 2016 primary, older voters still dominated the electorate.

The new figures are a reminder to activists: while outreach to every cohort is important, our state simply doesn’t have enough young people to determine the outcome of a midterm election.

I created the next two tables using numbers from the statewide statistical report dated August 17 and available on the Iowa Secretary of State’s website.

The first table shows the age distribution for all Iowans who voted in this year’s Democratic, Republican, or Libertarian primaries.

Turnout by age group, Iowa 2018 primary election
Age	18-24	25-34	35-49	50-64	65 and over	total
Registered	228,787	372,292	484,352	541,312	497,983	2,124,727
Total voted	10,966	23,887	42,327	81,602	129,967	288,749
Turnout rate	4.79%	6.42%	8.74%	15.07%	26.1%	13.59%
Percent of ballots cast	3.8%	8.3%	14.7%	28.3%	45.0%	100%

People over age 50 represent about half of all registered voters in Iowa, but they are much more likely to participate in a primary. Senior citizens had the highest turnout rate and cast more ballots than did any other age band. Iowans over 50 cast 73.3 percent of the ballots.

I was particularly interested in the Democratic figures. Competitive races for governor and in three Congressional districts produced the second-highest ever Iowa Democratic primary turnout, surpassed only by the June 1990 election. The campaigns of Cathy Glasson and Nate Boulton had invested heavily in outreach to young Iowans, as did several candidates for other offices. How much would that change the composition of Iowa’s electorate compared to the 2016 primary, when nearly 80 percent of Democrats who participated were at least 50 years old?

Here’s the age distribution for this year’s Democratic primary voters:

Turnout by age group, Iowa 2018 Democratic primary
Age	18-24	25-34	35-49	50-64	65 and over	total
Registered	55,555	103,244	136,612	175,427	194,494	665,332
Total voted	7,914	17,770	28,341	50,134	76,682	180,841
Turnout rate	14.3%	17.2%	20.8%	28.6%	39.4%	27.2%
Percent of ballots cast	4.4%	9.8%	15.7%	27.7%	42.4%	100%

Note the nearly threefold increase in the turnout rate among Democrats under age 35, compared to the 2016 primary. Here are the numbers from two years ago:

Turnout by age group, Iowa 2016 Democratic primary
Age	18-24	25-34	35-49	50-64	65 and over	total
Registered	57,575	107,862	137,138	183,012	182,009	667,596
Total voted	2,764	6,111	11,991	29,970	50,262	101,098
Turnout rate	4.8%	5.7%	8.7%	16.4%	27.6%	15.1%
Percent of ballots cast	2.7%	6.0%	11.9%	29.6%	49.7%	100%

The turnout rate for older Democrats rose more modestly from the last primary to this year’s. However, there are hundreds of thousands more registered Democrats in the older groups, so in absolute terms they still cast several times more primary ballots than did millennials. About 70 percent of 2018 Iowa Democratic primary voters were at least 50 years old, 14 percent were between the ages of 18 and 34, and 16 percent were between the ages of 35 and 49.

As a group, general election voters in Iowa skew less old than do those who take part in primaries. Nevertheless, voters over 50 will likely cast at least 60 percent of the ballots in the November election. Bleeding Heartland covered the age breakdown of Iowa voters in the last three midterm elections here.

Any relevant comments are welcome in this thread.