About 30 minutes into our conversation about his brother, Tobin Ryan pauses and tells me that he can remember the details of that August day, 26 years ago, almost to the minute.

That morning, Tobin, then days away from starting his senior year at Notre Dame, woke up early. After a quick shower, he stepped quietly out of his family’s home in Janesville, Wis.

Tobin headed to a nearby restaurant. For an hour, he and one of his favorite high-school teachers reminisced and laughed. They talked about Fighting Irish football and old friends.

After coffee, Tobin and his former teacher shook hands and Tobin turned toward home. As he neared his house, he spotted an ambulance and strange men on his driveway.

“The paramedics were already there,” Tobin recalls, and their grave faces signaled what they would soon tell him.

His father, Paul M. Ryan, age 55, was dead.

Tobin’s younger brother, Paul D. Ryan, nicknamed P.D. by his three siblings, was inside. Paul, then 16 years old, had found their father while Tobin was at breakfast.

P.D. was alone. Their mother, Betty Ryan, was in Colorado visiting her family. Janet, their sister, was away from home, as was Stan, their older brother, who was working for IBM in upstate New York.

Their father’s secretary had called the house, frantically asking whether their father, a prominent local attorney, was coming to work. There were clients at the firm and they were getting impatient.

Paul put down the telephone and strolled down the hall to check on his dad. “Even though he had probably been dead through the night, Paul tried to resuscitate him,” Tobin says. His brother, this carefree teenager who flipped burgers at McDonald’s, did not panic. He tried mightily to do something, Tobin says, but their father’s heart had stopped.

“I’ve done a lot of reflecting in the past few days about what makes Paul tick,” Tobin says, and to him, much of his brother’s life can be understood by considering the events of that summer morning and their aftermath. Paul Ryan’s steadiness that day was impressive, Tobin says. But it was his perseverance after their father’s sudden death, through the end of high school and beyond, that defined him.

“Just twelve years later, in 1998, my brother was elected to the House,” Tobin says. In little more than a decade, Paul went from a fast-food kitchen to Congress, with stints as a think-tank speechwriter and star congressional staffer in between.

On the outside, his younger brother was easygoing and upbeat during the late 1980s, even when things were bleak inside the home. He rarely wallowed, Tobin says. Instead, he played soccer, and he was elected prom king and class president. But when they’d talk long into the night, brother to brother, Tobin knew that Paul was preparing for something bigger.

Soon after their father passed away, Paul was driven by a relentless “intellectual curiosity,” Tobin says, and his self-teaching “accelerated his development,” both personally and politically. Taking a cue from Tobin and Stan, who both majored in economics at Notre Dame, Paul majored in the same subject at Miami University in Ohio. Sitting in his dorm room, Ryan devoured the works of Friedrich Hayek and Ayn Rand.

“He absorbed it, he had a thirst for it,” Tobin says. “He read everyone, any author who could help shape his views or challenge how he saw things.” His older brothers “often went through the motions,” Tobin chuckles, “but Paul dove in.”

“The sense of purpose was always there, and frankly, it’s something I always found amazing,” Tobin says. “Here he was, our little brother without a care in the world, and then in this short period, he develops this worldview and skill set.”

Politics, however, wasn’t always on the agenda. After graduating from Miami in 1992, Paul Ryan went to work for Jack Kemp, the former supply-side congressman. That research-heavy experience almost led him to graduate school.

“At the time, Paul was thinking that he could become a pretty capable economist. He considered going back to get his Ph.D. and pushing the thought process in academia,” Tobin says. “But working with Kemp really changed his mind on that.”

One day in the mid-1990s, Tobin visited his brother at Kemp’s office. “Kemp put his hand on Paul’s shoulder and said, ‘Your brother is going to make a difference in this world,’” Tobin says. “That encouragement meant a lot.”

“Working with Kemp was Paul’s coalescing moment,” Tobin says. “It brought together his love of policy and economics, and it also made him look seriously at public service.”

Paul would go on to work for Senator Sam Brownback of Kansas, and he stayed close with former Wisconsin senator Bob Kasten, who gave him his first job in Washington. But it was Kemp, Tobin says, who was and remains Ryan’s hero.

“His political rise has been through policy, and that approach has made all the difference,” Tobin says. “When there was an open seat for the Senate, for example, he didn’t even pause to consider it because he knows that being budget chairman gives you more of an influence over the direction of public policy.”

But Ryan is more than a budget wonk. Mastering fiscal policy is important to the congressman, but it is not the sole reason for his success. Grit is another key element, Tobin says, and he credits his mother for instilling Ryan’s character.

Over the past weekend, a week after Mitt Romney introduced him as his running mate, Ryan campaigned in Florida. His mother, who now lives there, joined her son on the stump. Seeing them together, holding hands under the hot sun, reminded Tobin about the similarities between his mother and his younger brother. Betty Ryan, with her outgoing, plucky spirit, did much to encourage her youngest son.

After their father died, Paul wasn’t the only Ryan who rededicated himself to his family and his education. Betty Ryan, for her part, knew that she too had to chart another path in the wake of her husband’s unexpected death. “She went back to university here in Wisconsin, commuting up to Madison every day,” Tobin says. “She got a second degree, then became an entrepreneur and built a business.”

It wasn’t an easy time, Tobin says. Paul Ryan was still in high school; Betty’s mother, who had Alzheimer’s, was living in the home; and Betty was trying to learn a new trade.

“Mom, I am proud of you for going out and getting another degree. I am proud of you for the small business that you created, and Mom, you did build that,” Ryan said on Saturday, referencing President Obama’s infamous business remark. Betty Ryan beamed at her son, the veep nominee, as the crowd roared.

“The four of us kids, as well as my mom, we always knew we were going to create something good out of this,” Tobin says, thinking back to August 1986. “Rather than keeping our feet in the mud, which was tempting, we stuck together.”

These days, even as his brother becomes an especially prominent national political figure, Tobin does not expect him to change. “When Paul gave that first speech on the USS Wisconsin, he looked at his microphone for a second and said our dad once told us that you choose to be part of the solution or the problem,” he says.

“You don’t know what that meant to us in the family,” Tobin says. “Growing up, our father used to always say that, and we’d roll our eyes. Then, when your father dies, those teachings and phrases, well, they can take on greater meaning.”

“Our dad would say that in his calm voice all of the time, ‘Be part of the solution or the problem.’ Paul really took that to heart after Dad died. And I think, when you look at his views, if anything shapes his ideology, it’s that. He wants to throw himself into the solution.”

— Robert Costa is a political reporter for National Review.