Editor’s Note: Errol Louis is the host of “Inside City Hall,” a nightly political show on NY1, a New York all-news channel. The opinions expressed in this commentary are his own.

(CNN) —  

At one point in the course of a difficult evening in which he was pressed on his record and rhetoric about gun control, Republican Sen. Marco Rubio worried aloud that the national debate about gun control might trail off into yet another deadlock.

“Our attention span in this country on virtually every issue is 7 to 10 days,” Rubio told the crowd at CNN’s town hall Wednesday night. “And then we pivot. We’re one tweet or one story away from focusing on something else.”

He needn’t have worried. The powerful, laser-focused energy of the students, parents and teachers of Marjory Stoneman Douglas High School is part of an inspiring awakening of children and families determined to shake America from its national slumber on gun violence.

One student, Ryan Deitsch, talked about huddling as a 5th grader when his elementary school went into lockdown, and then needing to do the same at Marjory Stoneman Douglas High School last week. Describing active-shooter drills, lockdowns and code reds, he said: “They’ve been a part of my life for as long as I can remember.”

That sad, unacceptable reality is what makes the current debate about gun control different from the political impasses that followed past school massacres. Millions of children have grown up in the shadow of terror and violence, watching one school massacre after another – and the Parkland students, like many others now, are saying no more.

They are also wondering why lawmakers haven’t done more to control the spread of high-powered rifles, improve background checks and keep schools safe.

As Deitsch put it: “Why do we have to speak out to the capitol, why do we have to march on Washington, just to save innocent lives?”

Most of the town hall’s outpouring of grief and anger was aimed at Rubio, a longtime recipient of NRA funding.

“Your comments this week and those of our president have been pathetically weak,” Fred Guttenberg pointedly told Rubio. His daughter, Jamie, was killed at the high school. “Look at me and tell me that guns were the factor in the hunting of our kids in this school this week. And look at me and tell me you accept it and you will work with us to do something about guns.”

The audience cheered.

The two Democrats on stage – Sen. Bill Nelson and Rep. Ted Deutch – came in for tough questioning, too. Samantha Grady, a junior who was shot twice and saw a close friend killed, asked Nelson: “What are you going to do to strengthen background checks?”

Nelson, who is up for re-election this year, used every opportunity to attack Republican Gov. Rick Scott, who declined an invitation to participate in the town hall. In what seemed like a preview of the fall campaign, Nelson pointed out that Scott supplied financial incentives to gunmakers that make the kinds of high-powered rifles used in recent massacres.

The passion and forcefulness of parents and students, and their repeated demands for limits on assault weapons made so much of an impression on Rubio that he publicly announced he is rethinking his past opposition to putting limits on the size of ammunition magazines. He also said he would support legislation to prevent an 18-year-old from buying a rifle.

But the harshest words of the night were reserved for the NRA.

“Was the blood of my teachers and my classmates worth your blood money?” a student named Michelle Lapidot asked, even before Dana Loesch, representing the NRA, took the stage.

Loesch said the problem isn’t guns, but inadequate enforcement of existing federal and state laws. “This individual was nuts. … None of us support people who are crazy, who are dangerous to themselves, who are a danger to others, getting their hands on a firearm,” she said.

That brought a cascade of murmurs and booing.

With only a few weeks left in Florida’s legislative session, it’s unlikely the state will see major regulations become law. But the town hall reflects the beginning of a larger, national round of political organizing that will seek to organize and mobilize a steadily rising wave of 18- to 24-year-old voters.

After years of living in the shadow of fear, they are building power around the simple, powerful slogan: never again.