Richard Lee Whitley needed a lawyer.

The Northern Virginia handyman had confessed to murdering a neighbor and then sexually assaulting her with umbrellas, and the volunteer lawyer handling his case had just moved out of state. It was 1983, the Supreme Court’s suspension of the death penalty had just ended, and Whitley faced death row.

Enter Tim Kaine. The attorney had only been out of law school for a few months, and had just moved to Richmond. A devout Catholic, he’d already developed a reputation as a committed opponent of the death penalty, so when Whitley’s representation problems made his execution more likely, Kaine’s name came up as someone who might help.

And after hesitating, he took the client.

Over the course of his career, Kaine didn’t just oppose the death penalty; he worked to prevent executions by representing men facing death because they committed murders. His dogged opposition to the death penalty presents a stark contrast with Donald Trump’s stance on the issue, but it also differentiates him from his own running mate, Hillary Clinton.

The death penalty is not a top political issue this cycle. At all.

Americans are much more concerned about, well, just about anything else—especially the economy and terrorism.

But in Philadelphia last month, Democratic National Convention delegates voted to officially back its abolition in their platform. It was not only historic—but it was also more in line with their nominee’s running mate than Clinton herself. The former secretary of state has long refused to completely rule out its use, and as recently as March cited the 9/11 attacks as potentially justifying it.

So for Clinton, it’s complicated. But for Kaine, it’s not.

Since his first days as a lawyer, Kaine has put in hundreds of hours, for free, to get murderers off death row. His first, formative case was Whitley’s, who confessed to slashing the throat of a 63-year-old woman living in his Fairfax County neighborhood and then using two umbrellas to sexually assault her.

Whitley’s lawyer quit during the sentencing process, Kaine had only been practicing law for six months. But he was plugged in to Richmond’s anti-death penalty circles, and the Virginia Coalition of Jails and Prisons—which shared office space with the state’s chapter of the American Civil Liberties Union—recommended he represent Whitley, according to the Richmond Times-Dispatch.

At first, Kaine said no.

“But then it kind of worked on me that I had said no because my feeling is, well, I say I’m against the death penalty,” Kaine told the Virginian-Pilot for a 2005 profile. “If I say that’s my belief but I say, ‘Nah, I’m not going to do it,’ then I’m a hypocrite.”

He ended up putting in about 1,000 hours of work for Whitley, according to the Times-Dispatch , most of it for free.

He couldn’t stop the execution. On the day of Whitley was scheduled to die, Kaine addressed news cameras while holding a Bible.

“Murder is wrong in the gulag, in Afghanistan, in Soweto, in the mountains of Guatemala, in Fairfax County... and even the Spring Street Penitentiary,” he said, according to The Washington Post .

And he cited his faith.

“I think it’s outrageous that there is the death penalty,” he said, according to the Times-Dispatch. “It’s not the biggest outrage in the world, but it’s one of a number of outrageous [things] where people don’t appropriately value the sanctity of human life.

“I think it’s a religious perspective,” he added. “I spent a year in Central America working in a Jesuit mission and saw an awful lot of hunger and infant deaths caused by malnutrition. The essence of human life is probably suffering and pain... The thing that redeems that is the presence of God in every person.”

That day, Kaine sat outside Whitley’s cell for several hours with one of Whitley’s friends and a priest.

In a speech earlier this year , Kaine recalled that they shared his last meal and talked.

“If nothing else, I wanted my client to know that I did all I could and never gave up on him,” Kaine said. “He hadn’t experienced that very much from the people in his life.”

The Times-Dispatch characterized Kaine’s work for Whitley as “a substantial part of his career.” Kaine told the Virginian-Pilot that Whitley became a Christian while he was representing him.

Later, Kaine defended Lem Tuggle, who sodomized, raped, and murdered a 52-year-old woman shortly after getting out on parole (he had previously murdered a 17-year-old girl).

While driven by his Catholic beliefs, Kaine’s actions for the violent and condemned have been used by political opponents to try to take him down.

In his 2005 gubernatorial race, Republicans ran two TV ads, in particular, targeted him. In one , the wife of a murdered police officer said, “When Tim Kaine calls the death penalty murder, I find it offensive.”

Another ad got more attention. In it, the father of a murdered man spoke over soft piano music and criticized Kaine’s efforts to keep convicted murderers from being executed.

“Tim Kaine says that Adolf Hitler doesn’t qualify for the death penalty,” the narrator said.

It was an overreach.

Kaine aired a rebuttal ad that would define his political career. In it, he spoke directly to the camera about his stance on the death penalty and promised to enforce it if elected.

“As governor, I’ll carry out death sentences handed down by Virginia juries because that’s the law,” he said.

According to a memo from his pollster , Kaine’s campaign team anticipated that his stance would be a liability for him, and they had Kaine pre-tape the ad months before Republicans hit him. And they showed the ad to focus groups to make sure it would work.

When Kilgore’s ad went up, they were ready.

Some Virginia Republicans say that if Kilgore’s team had pushed their first ad—the one that didn’t mention Hitler—instead of the Hitler one, Kaine still might have lost.

Instead, he went on to win two statewide races in the Old Dominion.