PARKLAND, Fla. (Reuters) - A year after the deadliest high-school shooting in U.S. history, students from Florida’s Marjory Stoneman Douglas High School look back with pride on the network they have built to stem the country’s epidemic of gun violence through the ballot box.

FILE PHOTO: Emma Gonzalez, a student and shooting survivor from the Marjory Stoneman Douglas High School in Parkland, Florida, addresses the conclusion of the "March for Our Lives" event demanding gun control after recent school shootings at a rally in Washington, U.S., March 24, 2018. REUTERS/Aaron P. Bernstein/File Photo

Even so, it has been difficult for many to come to terms with the trauma of Feb. 14, 2018, when a former Stoneman student with an assault gun massacred 17 people at the Parkland, Florida campus.

“There’s definitely not a day that goes by where I’m not thinking about it, and I know for a fact that everyone that has to walk through those campus gates is thinking about it,” said junior Caitlynn Tibbetts.

The student campaign in support of gun control, which featured a massive march on Washington and in other cities around the country, resulted in the formation of a sprawling national network called March for Our Lives.

With some 500 chapters, it has linked tens of thousands of student activists in pushing for political candidates who support their goals of new measures to reduce gun violence.

“We have to replace these terrible actors who are comfortable putting our lives at risk for a check from the NRA,” said Matt Deitsch, the group’s chief strategist, referring to the National Rifle Association, which opposes what it considers any retreat on gun rights.

Deitsch, along with Emma Gonzalez, David Hogg, Delaney Tarr and Jaclyn Corin, is among the most prominent Stoneman students who have toured the nation to encourage young people to register and vote for pro-gun control candidates.

By “terrible actors,” Deitsch was referring to political incumbents who oppose the group’s goals, which include a ban on assault weapons. It also backs funding for gun violence research and supports universal background checks, disarming domestic abusers and enacting laws to staunch gun trafficking.

“The fact that gun violence is a top issue for the first time ever is something that should scare the people arrayed against us,” Deitsch, 21, said with evident pride.

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Having put together a multimillion-dollar war chest, with the help of A-list celebrities like George Clooney, Oprah Winfrey and Steven Spielberg, the network aims to expand to thousands of high schools and colleges by the end of 2019, giving it even more clout going into the 2020 election.

On Monday, activists were to launch a petition campaign to put an assault weapons ban on Florida’s ballot in the 2020 election. March For Our Lives leader Hogg, among the first Stoneman students to call for greater gun control in the hours after the shooting, was expected to attend the campaign kickoff, along with parents of some of the victims. The petition needs 800,000 signatures.

“I’M A HUMAN BEING”

Success has come at a cost for the student activists. Since last year’s shooting, many have not had enough time to grieve or properly process the tragedy.

In a series of recent Twitter messages, Tarr, a March for Our Lives co-founder, reflected on having to put on a composed “performance” over the past year as a public figure on social media.

“I can’t sit back and let you think that I’m always fine, that I’m always ready to go. That’s not realistic,” she wrote. “I’m a human being and god damn if all of this work and pain isn’t hard.”

The past year has brought more U.S. gun violence, complicating the task of recovery. In a shooting with echoes of Parkland, a gunman at Santa Fe High School in Texas killed 10 and wounded 14 on May 18. Months later, an anti-Semitic attack on the Tree of Life Synagogue in Pittsburgh left 11 dead and six injured.

By the end the year, that pair of shootings, combined with hundreds of others, left a total of 387 dead, according to the Gun Violence Archive.

“We carry a heavy weight, and every single day there’s another mass shooting in America, and we see ourselves as vessels amplifying what’s going on this country,” Deitsch said.

For many students, sharing their experiences, both broadly and with those who have gone through something similar, has been therapeutic, however.

Not long after the shooting, a publisher contacted Sarah Lerner, a journalism and English teacher at Stoneman, about publishing a book filled with reflections of that day and its aftermath.

“Parkland Speaks: Survivors from Marjory Stoneman Douglas Share Their Stories” was released late last month and includes 43 accounts of the shooting and what followed, including two pieces by Tibbetts, the junior.

“This book gave us the opportunity to look past politics and look at the heart of it,” Tibbetts said. “And the heart of it is that we’re struggling to move past it, but we’re trying.”