In a T-shirt emblazoned with the words "Voice, power, change," the lanky teen stepped up to a crowded podium on the steps of the Minnesota State Capitol on Saturday and took a deep breath as he looked out at a sea of people that stretched beyond his view.

Ben Jaeger, a 16-year-old student organizer from Roosevelt High School in Minneapolis, had rehearsed the speech he hoped would rouse his fellow students to push lawmakers for more gun control, but he hadn't expected a crowd of 20,000 people in front of him. He found the moment electrifying.

"We must demand a safer state and a safer nation," Jaeger said. "We the students, and we the youth, are the future."

In St. Paul and a few other communities across Minnesota, students found new power and energy as they led March for Our Lives demonstrations, part of a nationwide protest calling for school safety measures and stricter gun laws. Students in Parkland, Fla., sparked the movement after 17 students and staff members were killed there in mid- February in one of the nation's deadliest school shootings.

The day was filled with optimism that even students too young to vote could still push for change, Jaeger and others said. A crowd of students first gathered at Harriet Island Regional Park in St. Paul, then marched through a bitter wind across downtown chanting slogans that included "Books not bullets." Students at the front carried a banner with the words "One is too many." Other marchers carried a large cardboard replica of an AR-15 rifle that they later planned to ceremoniously destroy. A woman stood along the route handing out juice and candy.

When the marchers arrived at the Capitol about a half-hour later, a crowd of several thousand more people — mostly adults — greeted them with cheers.

At the podium in front of the Capitol, a steady stream of speakers took turns delivering speeches both rousing and tearful.

Sen. Matt Little, DFL-Lakeville, criticized a lack of action in the Legislature in recent years. "They've done nothing. They are doing nothing. And they plan to do nothing," he said. "But that's about to change."

Little and three other state senators, including two Republicans, have spoken out in favor of universal background checks for gun sales and transfers, as well as mandatory reporting of lost or stolen firearms.

At times on Saturday, the crowd shouted "Vote them out," with activists saying they will no longer tolerate elected officials bowing to the National Rifle Association.

But the mood turned somber when parents and students associated with Parkland's Marjory Stoneman Douglas High School hockey team — in Minnesota for a national tournament — stood up to embrace each other and deliver tearful speeches about the horrors at their school.

Parkland student Stephanie Horowitz cried as her brother Matthew, a hockey player, held her on the podium.

"My friend had to hold my friend's hand while she passed away," she said, her voice cracking. "Now I have to look at her empty desk every day … I'm marching in her name because she can't anymore."

"We love you!" people yelled back, many wiping away tears.

Before the speeches, Mariah Bruner, an 18-year-old senior at St. John's Prep in St. Cloud, said she had come with a friend to support more gun control measures, specifically raising the legal age to buy a firearm and stricter background checks.

Though Bruner hunts deer and turkey with her family, she cited a difference between hunting rifles and the more destructive weapons used in some shootings.

"There needs to be a line," she said. "A rifle for hunting is different than a rifle that can shoot out that many rounds at a time."

Bruner said she was amazed and encouraged at the size of the crowd. "Solidarity is what's going to make the change," she said.

"There's no reason for an average citizen to have such a powerful, powerful weapon," Normandale Community College student Nicole Reiling, 18, said.

Adults marveled at the thousands of students who left warm beds to march on a cold and windy morning.

Katie Carter, a biology teacher at Roosevelt High School in Minneapolis, held a sign saying, "I teach the generation who will save us all." She said she was proud to see Jaeger, one of her students, leading the charge.

"I'm glad that, for whatever reason, we're getting more movement," Carter said. "It's the same tragedy, but different with their voices being heard."

Before the crowd dispersed, it stood in a moment of silence as the ballad "Shine," written by two Parkland students, reverberated over the Capitol grounds:

"We're putting up a fight," the lyrics went. "Together we will shine the light."

liz.sawyer@startribune.com 612-673-4648 miguel.otarola@startribune.com 612-673-4753 pam.louwagie@startribune.com 612-673-7102