Chris Murphy has tried to find the right words.
After a gunman killed 20 children and six educators in a Newtown, Connecticut, elementary school in 2012, the senator spoke with families of the victims, people whom he now calls friends. He wanted to understand, in whatever way he could, the effects of an American epidemic that he sees as his "mission" to treat.
"That's a day that changed my life," Murphy, 47, said in a recent interview.
Four years later, after a shooter killed 49 more people at an Orlando, Florida, nightclub, Murphy made his most memorable plea on the Senate floor — speaking for 15 hours in one of the longest filibusters in U.S. history.
"I'm prepared to stand on this floor and talk for, frankly, as long as I can because I know that we can come together on this issue," he told his colleagues then, though he knew he was addressing a Senate sharply divided on how to prevent gun violence.
Only two Republicans — Sens. Ben Sasse and Pat Toomey — came to the floor to listen to Murphy and ask him questions about his plans.
Seven years after that, Murphy still finds himself talking to a divided chamber.
And he keeps going. Recently, with Democrats regaining control of Congress and the White House, Murphy reintroduced a bill that would expand background checks to firearm sales by private sellers, such as at a gun show.
"We're going to save thousands of lives," Murphy says of that legislation, should it become law. "But I also know we're going to rescue millions of kids from lifetimes of trauma that are totally unnecessary."
'Persuaded by Politics'
Gun violence — which saw only an illusory respite amid the COVID-19 pandemic — continues to kill approximately 40,000 people annually, including suicides, with major mass shootings in recent weeks in Colorado, Georgia and Indiana.
"We have to act," President Joe Biden told reporters after last month's supermarket massacre in Boulder.
Biden went on: "The consequences of all this are deeper than I suspect we know."
Acting now to prevent more deaths in the future has been Murphy's plea to lawmakers on Capitol Hill time and time again since Newtown nearly a decade ago. He speaks candidly about the opposition to his reforms and where he places his blame.
"Republicans are not going to be persuaded by facts," he tells PEOPLE. "They're going to ultimately be persuaded by politics, the consequences to them by voting the wrong way, and by emotion."
Many conservatives, by contrast, support a far more expansive view of the Second Amendment than Democrats like Murphy and argue his reforms are unconstitutional. Critics of Murphy's work say the problem is misstated — that it isn't the prevalence of guns but rather the gunmen themselves.
There are some signs, however, that the national conversation may be changing.
The National Rifle Association — long a lobbying group that helped shaped GOP response to gun legislation — filed for bankruptcy earlier this year.
Meanwhile, "90 percent of people in the country" support broader laws on background checks, as Murphy is often quick to point out, sounding confident his efforts may finally see a political breakthrough. (Polls consistently show the public backs stricter gun laws overall, including banning assault-style weapons.)
The latest spate of mass shootings was a stark reminder of what is at stake, according to Kris Brown, president of the Brady gun violence prevention organization.
"Nothing has changed in this," Brown tells PEOPLE. "The only difference is our arguments and our case has improved — because our situation has gotten worse."
After the shooting in Colorado, Murphy again walked to the Senate floor. This time, he read the victims' names aloud to his Republican colleagues.
It's a bet on the future, not a guarantee. "The emotional connection to this issue that Congress-members have will ultimately win the day," he says.
That is, ultimately, what also drew him to the issue nearly a decade ago.
'It Was Just Inconceivable to Me'
Murphy still sounds mystified when he talks about the Newtown shooting, which shifted the course of his career. He pauses pensively — with plenty of "ums" — while searching for the words that many gun-violence victims' families say don't exist.
"Sandy Hook is an idyllic small town, probably one of the least violent places in the world," Murphy says. "It was just inconceivable to me that this place that I knew so well could have this kind of evil inside of it."
The senator first got word of the killings while waiting at a train station for a holiday trip to New York City with his family. Rushing to drive from the train to Sandy Hook Elementary School, Murphy followed the same gut-wrenching routine familiar to such mass shootings: listening to breaking news reports and grimacing each time the number of dead rose.
After Murphy arrived in Newtown, he met with community members at a nearby firehouse and joined them in the impossible work of trying to console the families who just lost a child.
"I can't imagine what that must have been like," Brown, the Brady president, says now. "But I know that through fire, different things are forged in people. You either emerge or you perish."
Murphy, she says, "emerged as a relentless leader."
Years later and he still stays in touch with some of those families "nearly every day," he says.
'He's the Conscience'
Since Sandy Hook, Murphy has spent years learning about America's history with guns — from understanding legal loopholes in background checks to the different types of assault-style weapons to examining the links between poverty and violence.
He is never far from the issue.
During one Friday morning visit to Baltimore's Matthew A. Henson Elementary School in 2019, Murphy was meeting with teachers when the classroom lights suddenly shut off and a voice called out over the intercom above: "Code green! Code green!"
A shooter in the area forced the school on lockdown, he quickly learned. Less than five blocks away, 25-year-old Corey Dodd had just been shot and killed after dropping off his twin daughters for class minutes beforehand.
"I was in that school for two hours total," Murphy says, still sounding mystified years later. "I can't imagine how many times that's happened if, [just] during the two hours I was there, I experienced an active-shooter lockdown."
A year later, Murphy wrote a book, The Violence Inside Us, tracing the history of a nation he describes as obsessed with guns and confoundingly apathetic toward the violence firearms can cause — despite everyday stories like Dodd's.
Murphy's goal of reform, long stymied by a polarized Congress, is again on the table. He believes Americans "should expect" change to happen this year, now that Democrats have unified — though tenuous — control of the federal government through 2022.
"The voters have done their job," the senator says. "Now, it's up to Congress to deliver."
Murphy made the first move in early March, reintroducing his Background Check Expansion Act.
An identical proposal had passed the Democratic-led House of Representatives in 2019 but never came to a vote under the Senate's Republican majority. The bill would force private sellers to run background checks on people to whom they are selling guns.
"In many states, gun shows and internet sales aren't required to have background checks attached to firearm sales," Murphy says. "Our bill makes sure that no matter where you buy a gun in this country, you have to go through a background check."
Democrats will need 60 votes in the Senate to overcome a filibuster — or, less likely, toss out the filibuster entirely — in order to pass gun legislation. That means 10 Republican votes, a Murphy has yet to procure.
Reformists are also under pressure from advocates who want to move even more sweepingly to restrict gun use, rather than more incremental changes on background checks.
Joe Biden's White House is calling for congressional action, though he has taken action of his own: Earlier this month, Biden signed six executive orders he described as "common-sense steps" toward combating gun violence.
Among Biden's orders: restrictions on so-called "ghost guns" (homemade weapons built using kits, which don't have traceable serial numbers) as well as on the sale of stabilizing braces, which increase a gunman's accuracy.
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Next, the Biden administration is looking to lawmakers like Murphy, who was there with Biden shortly after the 2012 shooting when the then-vice president met with Sandy Hook families.
White House Press Secretary Jen Psaki, speaking about the party's efforts to pass new gun legislation, called Murphy "a leader" last month.
Anti-violence advocates also see Murphy's story of discovery as a blueprint for changing hearts.
"In his early life, I don't think the emotional component of this issue was as clear to him as it is now," Brown says. "To me, to some extent, he's the conscience."