For the first time, millennials next year will pass baby boomers as the largest generation of Americans eligible to vote, according to the well-respected demographic forecasts from the States of Change project at the Center for American Progress, a liberal advocacy group. That transition will end a remarkable four decades of dominance for the baby boomers, who have been the largest generation of eligible voters since 1978, when they surpassed what's been popularly referred to as the Greatest Generation (or G.I. Generation) raised during the Depression.
This steady shift in the electorate's composition should benefit Democrats. The baby boom, which is predominantly white, has drifted reliably toward the GOP in recent years: both Mitt Romney and Donald Trump carried about three-fifths of whites older than 45, exit polls found. By contrast, when compared to older generations, the millennial generation, which is more racially diverse and less religiously devout, votes more often for Democrats, expresses more opposition to Trump and professes more liberal views, particularly on social and environmental issues.
But the impact of this change will be muffled if millennials continue to vote at much lower rates than their elders, particularly in midterm elections like 2018. Though millennials are on track to soon surpass baby boomers as the largest generation of potential voters, experts caution that because of their lower turnout it may still be years until they exceed their elders among actual voters. With polls now consistently showing a huge generation gap over Trump in particular and the parties in general, the next several elections could hinge on how fast millennials convert their potential influence into actual power at the ballot box.
The long-term electoral shift from the baby boom and older generations toward millennials is unmistakable. The first millennials -- generally defined as the generation born from 1981 to 2000 -- entered the electorate in 2000. At that point, according to Census figures analyzed by States of Change, they represented just four percent of eligible voters; baby boomers (born between 1946 and 1964) constituted nearly 10 times as many eligible voters, at 39%. By 2016, the two generations had virtually converged, with Census figures showing that baby boomers represented just over 31 percent of eligible voters, and millennials just less than 31%. (In the process, millennials surged past Generation X, Americans born between 1965 and 1980, who comprised about one-fourth of eligible voters last year.)
The States of Change project, which studies the political and policy implications of demographic change, forecasts that will be the last time baby boomers outnumber millennials among eligible voters. In 2018, it anticipates, millennials (at just above 32% of eligible voters) will squeeze pass baby boomers (at slightly below 30%). The project expects that gap to widen to a nearly six-point advantage for millennials in 2020. Compounding the change, the first post-millennials -- young people born after 2000 -- will enter the electorate in the next few years.
In 2024 -- when it would not be unreasonable to expect the first millennial on a presidential ticket -- the States of Change project forecasts millennials and post-millennials will comprise nearly 45% of all eligible voters while baby boomers will shrink to just over one-fourth. (The forecast anticipates that Generation X will remain largely steady at about one-fourth of eligible voters over that period.)
Just before the first millennials entered the electorate, voters under the age of 30 split almost evenly between the parties in the 2000 presidential election and the three congressional elections from 1998 through 2002. But as millennials have poured into the voting booths, the youth vote has tilted sharply toward Democrats on both fronts (peaking with Obama's 66% support among voters under 30 in 2008). In 2016, Hillary Clinton struggled among young voters from the outset -- Bernie Sanders beat her among them in the Democratic primary by a wider margin than Obama did in 2008
-- and saw many of them defect to third-party candidates during the general election. But even so, Trump carried only a little more than one-third of voters under 30, no better than Romney's meager performance.
If anything, Trump appears to have lost ground among millennials since. Echoing other results, a mid-July ABC News/Washington Post poll
put his job approval rating among them at just 27%, much lower than any older generation. Surveys by other media organizations have found that over two-thirds of millennials oppose the House-passed legislation to repeal the Affordable Care Act
, Trump's decision to withdraw from the Paris climate treaty
, and his proposal to build a border wall with Mexico
. An early June Quinnipiac University survey
found that, by nearly two-to-one, millennials prefer Democrats over Republicans to control the House.
The big caveat to this trend is that both in the 2016 election and since Trump has demonstrated significant support among white millennials without a college degree
-- the children or younger siblings of the older working-class white voters at the core of his coalition. Overall, though, the trend line is clear: more millennials at the ballot box means better odds for Democrats in their struggle to overturn Republican dominance in Washington and most states.
But the big question remains how many millennials eligible to vote will actually do so. Using census data, the Pew Research Center calculated
that just under half of eligible millennials voted in 2016. That was a slight improvement from 2012, but still far below the turnout levels last year for Generation X (over three-fifths), the baby boom and older generations (both over two-thirds.) Despite rising to almost equal baby boomers in the eligible electorate, that much lower turnout meant millennials represented only about one-fourth of actual voters last year, compared to slightly over one-third for the baby boom.
History suggests that generation gap could actually widen next year. In both the 2010 and 2014 mid-terms, turnout among voters under 30 fell by more than half from the presidential election two years earlier, a steeper decline than among older generations. Fewer than 20% of eligible voters under 30 voted in 2014, the lowest figure for a mid-term election since 18-year-olds were given the vote in 1972.
Kei Kawashima-Ginsberg, director of the Center for Information and Research on Civic Learning and Engagement at Tufts University, which studies youth participation, thinks that pattern could break next year. "With a lot of conversations about resistance becoming more prominent and because of the lean of the generation toward the left, the importance of electing the Congress in midterms may have become more evident for them," she says.
Still, in a recent study
, Democratic pollster Celinda Lake projected that slightly more than half of millennials who voted in 2016 won't turn out in 2018.
Aging alone will resolve some of these issues. Experts such Kawashima-Ginsberg note that turnout among millennials is rising from presidential election to election at about the same modest pace as it did for baby boomers and Generation X. But because millennials started at a slightly lower turnout rate than boomers did, they continue to trail them in voting at the comparable point in their lives.
That gap largely explains why the States of Change project does not anticipate millennials will replace the baby boom as the largest generation of actual voters until 2024 and Pew demographic expert Mark Hugo Lopez predicts the tipping point may not come until even later. With age now such a stark dividing line in political allegiance, few dynamics may shape the balance of power between the parties over the next decade more than the speed at which that millennial wave crests -- and the baby boomer tide recedes.