A millennial cheers a boomer. (Photo by Lucian Perkins /for The Washington Post)

ALERT ALERT, the Wall Street Journal blared on its front page on Tuesday, MILLENNIALS UNSETTLE RACE.

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The aforementioned race being that for the presidency, and the unsettling referring to the disruption that's been unsettling baby boomers the country over: The decreasing demographic dominance of America's once-largest generation. "For the first time," reporter Janet Hook writes in her lead, "millennials will match baby boomers as a share of the electorate." Oh my God, boomers think, as they try to catch their breaths. What is this country coming to? Will they elect ... a selfie stick??

We will remind you that the term "millennial" doesn't have a hard-and-fast meaning. The Census Bureau recognizes only the boomers as a definable generation at this point, though it's not immune to the allure of using "millennial" to grab people's attention. "Millennial" essentially means "younger people" in a non-marketing context, and just how young those people are can vary widely. Pew Research figures that millennials are aged 19 to 35 -- the sort of gulf that makes lumping them together a little silly. There are millennials who have millennial babies, which sort of breaks the idea of it being a "generation." (Of course, there are also boomers who have boomer children, but let's not let that distract us.)

It's not clear how Hook is defining "millennial," but she writes that the percentage of all eligible voters from that group is 31 percent -- same as the boomers. Ergo, they "match baby boomers as a share of the electorate." (The grim fact underlying this shift? As millennials age, boomers are dying. Sorry, boomers.)

But it's important to note that "share of those eligible to vote" is not equal to "share of the electorate." Older voters still turn out to vote much more heavily than younger voters. So while the density of the millennial vote (using Pew's subjective delineations) in the overall voting population has increased, boomers are still a larger portion of those who actually vote.

Let's look at who turned out in Iowa and New Hampshire this year versus in 2008, the last time both parties had contested nominations. This is how turnout compared between the two.

The age distribution between the two is largely the same. In 2008, people under 40 were 18 percent of the Democratic vote in New Hampshire and 14 percent of the Republican vote. This year? 19 and 15 percent. In Iowa, the Republican turnout of those under 40 was 12 percent in 2008 and 2016 -- but turnout among those under 40 dropped from 23 to 18 percent among Iowa Democrats. In 2008, young people turned out in Iowa to vote for Barack Obama. In 2016, they were about as much of the electorate as the same age group was in New Hampshire.

But that's age ranges, not "millennials" -- which, we hasten to repeat, is a meaningless term. In 2008, millennials were all of the 18-to-24 age range and a slice of the 25-to-29-year-olds, per Pew's definition. This year, they've seeped into the 30-to-39-year-old range. But boomers and older were still more than 50 percent of the vote in New Hampshire and Iowa among both parties. (In N.H., 51 percent of Democrats and 57 percent of Republicans were 50 and over. In Iowa, 58 percent of Dems and 63 percent of Republicans were.) This is why Hillary Clinton eked out a win in Iowa. Young people strongly preferred Bernie Sanders, but they didn't come out as heavily. Older voters preferred Clinton, and they did.

There's not much reason to suspect that this trend will change for the general election. Older people -- who move less frequently and tend to work more stable hours -- vote more heavily, and will for some time. The arguments that Sanders will drag young voters to the polls haven't really held up so far this year, though the sample size is small.

Taking a point of privilege here, I will note that there are always groups of enthusiastic young people who assure the world that This Time Will Be Different and that Young People Will Change the World by Turning Out to Vote -- and then they don't. In 1992, a fifth of the electorate was under 30 -- down from eight years prior. As a function of all voters, people under 30 vote less than they did 30 years ago -- when the boomers were in that age group. It's on the increase in part because of the size of the post-1980 population boom. A lot of people were born in the 1990s.

If the broader worry is that older voters won't get to anoint their favored candidate, that Rubicon has been crossed. As I noted two years ago, the 2012 election was the first since 1976 that the oldest boomer age group voted for a candidate who didn't win the election. That year, 45-to-64-year-olds backed Mitt Romney, not Obama.

A consolation for the boomers: The youngest age group voting this year was born in 1998 -- after the end of the millennials, per Pew. By 2020, those post-millennials -- a group that still has no name despite MTV's marketing efforts -- will be creeping up on the millennials. ALERT. ALERT. The world keeps on spinning.