He was 18 then, working with two other college students, David DuPell and Ken Norbe, to build a political network that grew to 10,000 volunteers. Theirs was an early salvo in a movement that would end in 1971 with the ratification of the 26th Amendment, which lowered the voting age to 18 from 21.

Fifty years later, there is a nascent movement to change the voting age again — this time to 16 — but there are some big differences between the efforts.

Then, liberal and conservative activists united behind a powerful argument that went back to World War II, when President Franklin D. Roosevelt lowered the draft age to 18: Young people were being conscripted to fight America’s wars but couldn’t vote in its elections.

Today, there is no similarly popular argument.

Opponents in both parties have expressed doubts that 16-year-olds are mature enough to vote. But local, youth-led campaigns to lower the voting age have persisted since at least 2013, when Takoma Park, Maryland, gave 16- and 17-year-olds the right to vote in municipal elections.

In 1969, the voting age had been on the national radar for decades because of the draft. Through World War II, Korea and the early years of Vietnam, every president suggested it should change. But it didn’t — until the 1960s knocked American politics off its axis.

The activism of the era made it easy to mobilize liberals and students, many of whom were involved in the anti-war and civil rights movements. Now, just as college students did 50 years ago, many high school students are pointing to broad social turbulence that affects them and are seeking to influence the political process by voting.

A main objection is maturity. Jennifer C. Braceras, a senior fellow at the conservative Independent Women’s Forum, argued in a Boston Globe op-ed that 16-year-olds “don’t have enough skin in the game.”

But as expressed by the teenagers leading local voting-age campaigns, the rationale is that between climate change, gun violence, student debt and other issues, they do have skin in the game.

“The 16-year-olds right now will be the ones who live with the consequences of the choices the adults make right now,” said Vikiana Petit-Homme, 17, a high school senior in Boston.

This article originally appeared in The New York Times.