WASHINGTON (Reuters) - As hundreds of thousands of young people protest for stricter gun laws at “March For Our Lives” demonstrations across the United States on Saturday, the Democratic Party and nonpartisan groups plan to register first-time voters.

That could be the easy part.

The hard part will be ensuring that they go to the polls in November to vote in midterm congressional elections.

“It’s on us,” said Sabrina Singh, a spokeswoman for the Democratic National Committee. “We have to make sure that even after young people march across the country, they take time to vote, to register and to actually turn out to do it.”

Organizers of the voter registration drive hope to sign up at least 25,000 people at more than 800 marches, a potentially big boost for Democrats who generally favor more stringent gun control, including over sales of assault-type weapons, bump stocks that allow semiautomatics to fire like automatic weapons, and tighter access to guns by young people and people who are mentally ill.

In America’s history of mass murders involving firearms, the February massacre of 17 students and staff at Marjory Stoneman Douglas High School in Florida has had at least one unusual outcome: it has prompted students to take a high-profile stand on gun control.

Their public statements, organized protests and upcoming marches planned for 80 U.S. cities have cast partisan politics over U.S. gun laws in a harsh light. They have also sent a message to Washington that many students are eligible to vote this year and more future voters are right behind them.

FILE PHOTO: Students gather during a rally held at the Prospect Park Bandshell for the National School Walkout in Brooklyn, New York, U.S., March 14, 2018. REUTERS/Andrew Kelly/File Photo

“March For Our Lives might just be the largest audience of exclusively first-time voters anywhere,” said Tappan Vickery, a volunteer coordinator with the nonprofit voter registration group, HeadCount.

Vickery has a team of nearly 5,000 volunteers mobilized to sign up first-time voters in 30 cities on Saturday.

“There are 4 million Americans who are turning 18 this year. Match that with the good deal of 19- to 21-year-olds who have never registered to vote. We’re looking at a sum that is one massive number of prospects nationwide,” said the group’s spokesman and mobilization trainer Aaron Ghitelman.

Other groups with plans to register voters on Saturday include Everytown for Gun Safety, NextGen and Giffords, named for former U.S. Representative Gabby Giffords, who was shot in the head in an attempted assassination in 2011.

Participation in U.S. elections by young voters is often low. A Reuters/Ipsos poll released on Monday showed that 64 percent of 18- to 29-year-olds said they would vote on Nov. 6; 27 percent said they would not. Nine percent said they were uncertain or declined to answer.

“The trend among young, first-time voters in midterm elections has never been anything great,” said Dr. Kei Kawashima-Ginsberg, director of the Center for Information and Research on Civic Learning and Engagement at Jonathan M. Tisch College of Civic Life at Tufts University.

The turnout has been steadily declining since 1990 and hit the lowest level, at 20 percent, in 2014, according to the U.S. Current Population Survey.

Yet Kawashima-Ginsberg said it is still important to maintain “conscious optimism about young people’s vote.”

“They feel the need to make a difference and because of that, Saturday’s march becomes an opportunity for their activism to impact their parents and relatives, whether they themselves turn out to the polls or not.”

Democrats said they intend to follow up with newly registered young voters mainly by text messages.

(This version of the story corrects to reflect that young voter turnout has been declining since 1990 instead of since 2014, paragraph 14, changes source of that information to U.S. Current Population Survey instead of Kawashima-Ginsberg, corrects title of Tappan Vickery to volunteer coordinator instead of volunteer, paragraph 8)