NEWTOWN - While Carolyn McCarthy’s son was learning to speak again, after being shot in the head by a deranged gunman, she was growing angry with her congressman for voting against a ban on assault weapons.

Two years had passed since her son’s wounding in the 1993 Long Island Railroad massacre, which also took the life of McCarthy’s husband and five others on a crowded train leaving Manhattan, and she was thinking about making her own bid for Congress. Her son urged her to run.

“He said to me, ‘Mom, if you don’t do this now, you’ll never know what might have been,’ ” McCarthy recalled last week.

Those familiar with the result — McCarthy served nine terms in Congress — might not know how much the grieving widow struggled with the decision to run before her son spoke those words.

But it’s the same struggle facing three Connecticut parents who lost loved ones in two of the most barbaric crimes in state history, following U.S. Rep. Elizabeth Esty’s scandal-driven exit from the Fifth District race,

Nicole Hockley and Mark Barden, who both lost first-grade sons in the 2012 Sandy Hook massacre, and state Rep. William Petit, who lost his wife and two daughters in the 2007 Cheshire home invasion, are mulling whether their stories of transformation will make a difference in Washington, D.C.

That’s a decision McCarthy, too, had to make.

“It was the hardest decision I ever made,” said McCarthy, 74, living the retired life in Florida. “But I have to say, if they have that fire in them that all of us do when we make a decision to run, then they need to run.”

It was unclear last week whether Petit would run for the GOP nomination, or whether Hockley or Barden would run for the Democrats. All three have suggested they might not.

But if one or more of them do run, it could energize voters who feel disenchanted with congressional gridlock and galvanize those who feel disengaged from the democratic process.

“It would be an amazing spectacle to see a wide-open race for the Fifth with both parties dumping in money to support two spectacular people running as candidates,” said Scott McLean, a professor of political science at Quinnipiac University. “But these people are accidental politicians, so they represent far more than two political parties; they represent major social issues in America today.”

Through their homegrown nonprofit, Sandy Hook Promise, Hockley and Barden have become two of the country’s most visible advocates of gun violence prevention, launching peer-based programs to help schools recognize red-flag behavior before it ends in violence.

Petit, who lobbied unsuccessfully against Connecticut’s repeal of the death penalty, has helped guide policy as a member of the Connecticut General Assembly’s Public Health Committee.

Pat Llodra, the former Newtown first selectman who led the community during its initial recovery from the Sandy Hook massacre, cautioned that the parents considering a run for Esty’s seat will have to resist being labeled as single-issue candidates.

“We want legislators who have passion, and oftentimes a single life-changing event stimulates that passion,” said Llodra, who retired last year. “But single-issue legislators do not make good policymakers, so we want them to hold onto their passion but to think broadly.”

McCarthy said that was one lesson she learned while pushing for gun policy reform — and losing all but a few fights.

“They called me ‘The Gun Lady,’ and said I only had one issue, but I said, ‘There’s no such thing as a woman who has only one issue,’ ” McCarthy recalled. “Whether it was education or health care or getting Hurricane Sandy relief, I made sure I was helping out all of my constituents.”

While Petit, Hockley and Barden have not signaled to party leaders in Washington or Hartford when they will decide, timing is everything.

Only a month remains before the major parties hold nominating conventions, and both have other candidates who have either declared or could declare their interest in Esty’s job. The two declared candidates are former Meriden mayor Manny Santos, a Republican, and former Simsbury First Selectman Mary Glassman, a Democrat

Voters meanwhile are looking for candidates who are brave, authentic, and service-minded, observers and party leaders say. Voters are weary of sending politicians to Washington who campaign on principles, only to practice expediency once they get there.

Esty admitted to mismanagement of allegations against a former chief of staff, who she kept on board three months after learning that he punched and threatened to kill a former aide in the D.C. office. Worse, for some constituents, was that Esty wrote a glowing recommendation that helped him land a job with Sandy Hook Promise.

The former chief of staff, Tony Baker, was fired by Sandy Hook Promise shortly before Hearst Connecticut Media broke the scandal story late last month. Esty has since said she would not seek a fourth term, and would spend her remaining time in office making amends.

As a result, the race for the most competitive House district in Connecticut is wide open.

‘The pain never goes away’

When McCarthy was deciding whether to run for Congress, she was balancing anger over the murder of her husband, anxiety about her son’s future and her own deep emotions of grief.

The turning point came when GOP Congressman Daniel Frisa broke a promise to her and voted to repeal the federal assault weapon ban in 1996. McCarthy’s son, Kevin, then 25, implored his mom to run.

Long Island Republicans wouldn’t let McCarthy run in a primary against Frisa, so she switched parties and beat the incumbent with 57 percent of the vote.

“We don’t talk a lot about victims, but there are a lot of us out there, and the pain never ends,” said McCarthy, who retired from Congress in 2015. “I was furious, and that passion I had was that another family wouldn’t have to go through this.”

But in 2012, a chronically isolated 20-year-old took his mother’s AR-15-style rifle from an unlocked closet, shot his way into Sandy Hook School and committed the worst crime in Connecticut history, killing 26 first-graders and educators.

“To be very honest, after what happened in Newtown, I broke down,” McCarthy said. “All those years I fought trying to get a ban on assault weapons and fighting for victims of gun violence.”

McCarthy said she has been encouraged to see the families who lost the most in the Sandy Hook massacre turn the corner on their grief and take up the fight she chose a generation ago.

Making the next step to seek a seat in Congress represents a commitment to the greater good, McCarthy said.

Llodra, a Republican, agrees.

“When you have a personal tragedy, it changes how your brain is hard-wired, and the depth of that hurt changes forever how we see things,” Llodra said. “That tragedy for Mark and Nicole opened them up to a broader understanding of how things can go differently - not just about weapons and guns.”

Hockley said as much last week after speaking with Democratic leaders in Washington D.C., about a potential run for Esty’s seat.

“If Mark or I decided to go for it, we might not have the broad political experience, but we have the ability to learn quickly and exercise good judgment,” Hockley said. “We could have a core issue and still be effective on opioids and immigration and trade.”

If it sounds like Hockley is speaking for both of them, she is. Hockley and Barden, who have developed a close friendship as co-founders and managing directors of Sandy Hook Promise, will decide either that one of them will run or that neither will, she said.

A top state Democrat said he could support either candidate.

“It’s still early and the race is still shaping up, but they are both great activists for issues that Democrats believe in,” state Democratic Party Chairman Nick Balletto said. “They would be great candidates.”

Petit, a first-term state legislator representing Plainville, did not respond to a request for comment late last week, but this is not the first time Republicans have urged him to run for Congress. In 2014, he told the GOP it was too soon after his marriage and the birth of his son to run.

Although Petit’s profile is similar to Hockley’s and Barden’s, as a man who has publicly transformed his tragedy into a selfless concern for others, he differs from them because he has experience in elected office, a top state Republican said.

“Bill has been in state politics and has worked on the public health committee,” said J.R. Romano, the state’s GOP chairman. “So in that respect he is different.”

Quinnipiac’s McLean said the appeal of Petit, Hockley and Barden would be hard for voters to ignore, were the parents to become candidates.

“They have used their pain and anger to really inspire people, because they have not allowed their tragedies to paralyze them,” McLean said. “Their life stories and political activism are going to gain a lot of notice from voters who would otherwise see this as a boring race.”

rryser@newstimes.com 203-731-3342