Holbein and Hillygus find that young voters aren’t apathetic about politics and political life. Just the opposite. “By multiple metrics, most young people are politically interested and motivated,” they write. “And, despite the increased rancor in American politics, some measures find young people to be even more interested in politics in recent years than in the past.”

The issue isn’t interest, it’s structure. It is difficult to get anyone to do anything for the first time, and that’s especially true for voting, which isn’t an easy process in the United States. Worse, many states are making it harder, with specific efforts to keep young people, and students in particular, away from the polls.

Last spring, for example, the Republican-controlled Texas Legislature outlawed any polling location that wasn’t open for the state’s 12-day early-voting period, a move that forced a number of colleges and universities to close temporary voting sites on their campuses. Republicans in Florida, likewise, effectively banned early voting at state universities with a law requiring “sufficient non-permitted parking” at all early voting sites. That’s an easy-to-meet requirement for rural and suburban locations, but it’s difficult for sites on densely constructed college campuses.

Even states that don’t target students and young people for voter suppression still require prospective voters to register if they want to cast a ballot. And that, Holbein said, is a real problem. “When you take away an arbitrary obstacle like voter registration, youth turnout goes up quite a bit.”

If you take a broader view of obstacles to the vote — if you look beyond administrative burdens like registration and voter identification — there’s the simple fact that being young is difficult. “Young people are coming into their own,” Holbein said. “They are leaving home, they are learning to be adults, and in that experience of managing their lives, voting is one of the things that falls by the wayside.”

Without experience and familiarity, young people lack the confidence to vote, to say nothing of other forms of political participation like canvassing or working the polls. They don’t think they know enough and don’t feel the kind of efficacy that drives older voters to the polls at high rates. The solution, Holbein and Hillygus argue, is comprehensive civics education that provides “knowledge and experience grounded in awareness of the factors that shape voter participation.” Young people, in other words, need to learn how to be citizens. And the extent to which we don’t teach those skills greatly depresses youth participation in politics.

Liberalizing voting laws and improving civics education are long-term projects. In the meantime, there are things a campaign like Sanders’s can do to improve youth turnout and bring those supporters to the polls. In addition to stoking interest, a campaign like Sanders’s can educate young voters about the process — not just by telling them to register, but also by walking them through the process itself and doing the work a civics curriculum should have already done.