Gun violence has produced a notable uptick in political engagement by millennials. Will it last until November? Photo: Michael Robinson Chavez/The Washington Post via Getty Images

Close observers of political trends are familiar with a phenomenon usually called the “midterm falloff.” Voters generally participate less in midterms than in presidential elections. But there are categories of voters — notably young and minority (especially Latino and Asian-American, and to a lesser extent African-American) voters — who regularly become a smaller percentage of the electorate in midterms. This “falloff” has become a big Democratic Party problem lately as young and minority voters have assumed a more central role in the party’s base. At the same time, Republicans have benefited in recent midterms from their strong position among the voters most likely to participate in midterms: older white voters. This disparate turnout pattern was a significant contributing factor to the GOP midterm wins in 2010 and 2014. The last time Democrats had a midterm “wave,” in 2006, they were performing much better among older voters (actually winning half the senior vote).

Going into the promising midterm election of 2018, then, Democrats have to worry about the “midterm falloff” undercutting the many positive things they have going for them, such as Trump’s low popularity (and the intensity of antipathy toward him), the historic tendency of midterms to produce losses for the party controlling the White House, a bumper crop of qualified candidates, and enormous activist enthusiasm. In one respect, the problem has become somewhat simplified: The exceptional diversity of the millennial generation means that youth and minority turnout are to a considerable extent the same phenomenon.

There were some early signs —notably in a large poll of millennials from SurveyMonkey released in March — that Democrats had finally found in Trump an X factor that would get young people to the polls. But as the election season drags on, there are signs the age gap in likelihood to vote is persisting, as Ron Brownstein notes:

[N]o more than about a quarter of eligible adults younger than age 30 have voted in any of the past five midterm elections. In 2010, voters under 30 represented just 12 percent of all voters, exit polls found, down from 18 percent in 2008. The share of ballots cast by voters under 30 likewise skidded from 19 percent in 2012 to 13 percent in 2014. Each time, the proportion of the ballots cast by seniors spiked by comparable amounts …

Recent polling offers ominous signs for Democrats that this pattern of demobilization could persist in 2018 … despite the Trump administration’s relentless focus on policies that reflect the priorities of his conservative older white base, from ending protection for the Dreamers, to building a border wall, to attempting to repeal the Affordable Care Act. Though surveys show those ideas all face intense resistance among younger adults, Stanley Greenberg, the veteran Democratic pollster, told me there’s a “very real risk” that Millennial turnout could lag again in 2018.

Brownstein cites a recent Pew survey showing that over-50 voters were following midterm election news nearly twice as often as under-30 voters. So perhaps Trump is not actually enough to get young voters to the polls — at least until 2020, when the president is (or is likely to be) on the ballot again. That would not be entirely shocking since, after all, Barack Obama’s strong popularity among young voters exhibited itself as a powerful force in 2008 and 2012 — but not in the 2010 and 2014 midterms.

It’s entirely possible that Democrats can overcome a recurrence of the “midterm falloff” among young voters by gains elsewhere in the electorate, most notably the college-educated suburbanites who have contributed to Democratic over-performance in off-year elections from Virginia to Arizona. But even modest improvements in millennial turnout could work wonders, given the large lean toward Democrats in that demographic (a net 27 points in the same Pew survey that showed desultory millennial interest in the election).

In a separate analysis, Stan Greenberg suggests Democrats need to sharpen their focus and eliminate their ambiguity about a particular issue that is motivating millennials strongly this year:

The [Greenberg] memo also recommends a second message it says will help turn out young voters: pushing for stricter gun laws. “Republican inaction on gun control … may be even more important as an attack because it is the top attack among the millennials who lag in enthusiasm compared to every other Democratic base group …”

The memo specifically warns Democrats not to hedge on this message, saying it becomes less effective when candidates also mention their support for the Second Amendment.

Targeted messages to any demographic, of course, are also heard by others who may have a very different reaction, as Brownstein reminds us:

Trump has unquestionably struck a powerful chord in older, blue-collar, evangelical, and rural white voters who feel threatened by the demographic and economic changes remaking America. As Republican pollster Kristen Soltis Anderson wrote last week in the Weekly Standard, “In focus groups … I often hear older voters on the right describe Millennials as a hostile force trying to take their country away from them.”

Democrats are almost certainly going to make gains in November, but nothing would reduce the magnitude more than unsuccessful efforts to mobilize millennials that do succeed in terrifying old white folks. They can take comfort, however, in the fact that, all in all, the most terrifying force in American politics resides at 1600 Pennsylvania Avenue. That may be just enough to rouse young people from their apolitical prejudices and get them to the polls in November.