History can repeat itself if we forget that “words matter,” Alabama’s junior senator warned as he reflected on a white supremacist attack that shook Birmingham in 1963.

Ku Klux Klan members killed four young girls when they blew a hole in the side of the 16th Street Baptist Church, a meeting place for civil rights leaders. Years later, Doug Jones was the prosecutor who finally went after two of the bombers.

“This case is something I live with every day, in a very good way,” the Democrat said Monday. “I think about it every time I walk on the floor of the Senate and into my office.”

An audience of congressional interns barely moved as Jones described the details of the crime and how it shaped his understanding of racism in America.

“That trial changes you. It changes you as a lawyer. It changes you as a person. It changes you as a public servant, whether you are a United States attorney or a United States senator,” he said. “You feel the compassion, you feel when you hear things said about our immigrant community, how bad things can go because of that.”

“I wish every lawyer could have a case that meant so much to so many people,” he said.

Discourse and violence are linked, said Jones, who sees “ugly” talk as a significant threat. 

“If we are not careful with our words in our debates today, we can have a similar disaster,” he said, without directly mentioning a string of violent attacks on African-American churches that ripped through the South this decade. “We need to just have policy debates and not talk ugly about people that don’t look like us or talk like us.”

Civil rights leaders in Birmingham 50 years ago fought to assert their voting rights, and those rights are still under attack. 

“I am concerned about voting rights,” Jones said. But the Alabama Democrat doesn’t see “racial animus” as the motivating factor today. “I don’t think that the voting rights that are attacked these days are based on race, per se — not the racial animus we have, but on political considerations,” he said.

Jones also plugged his bill, introduced earlier this month, that would create a panel to systematically review, declassify and release government documents related to unsolved criminal civil rights cases from decades ago.

And he pushed for broadband for rural communities when an intern asked him how to educate people in rural areas about civil rights cases.

“One of the things I did in the campaign a lot, I gave not this speech, per se, but I talked about these cases a lot no matter where I went,” he said of his successful special election bid against Republican Roy Moore. “I truly believe that in Alabama, like in so many other states, we really have more in common than we have that divides us, and we just got to talk about them.”

In 1998, Jones was a father of a high school daughter and newly appointed U.S. attorney for the Northern District of Alabama. The case about the bombing that left four young girls dead — Addie Mae Collins, Cynthia Wesley, Carole Robertson and Carol Denise McNair — was reopened.

Minority Leader Charles E. Schumer choked up and took a few seconds to compose himself as he introduced Jones to the group.

He said he had seen Jones’ presentation twice already and is extremely moved by it, joking that President Donald Trump calls him “Cryin’ Chuck.”

“As a second-year law student, Doug skipped class to attend the trial of the Klansman ring leader of these 1963 bombings of the 16th Street Baptist church. That, as you may recall, was an event that shook the conscience of our country and helped launch the civil rights movement,” Schumer said.

Jones took another look at the case more than 30 years after the bombing.

The senator showed slides to convey the details of the case. The bomb went off on the morning of Sept. 15, 1963, planted by a group that included Thomas Edwin Blanton Jr. and Bobby Frank Cherry.

Jones spoke to the group of interns as if it were a lecture for future lawyers. He described why photographs and recordings were used as evidence, why Blanton and Cherry’s personal lives and backgrounds mattered and why he chose each witness that he called to the stand.

Victim Carole Robertson’s mother offered her testimony on the first day of the 2001 trial on what would have been her daughter’s 51st birthday.

“The families were just remarkable. They had this abiding faith in our system of justice,” he said.

He concluded by reminding the interns: “At the end of the day, at the very end of the day, this is about social justice.”