Byron Dorgan spent 30 years representing North Dakota in Congress — 18 years in the Senate and 12 in the House. And there’s one constituent he thinks of when people ask how ordinary people can effectively lobby their representatives. She was a determined woman whose fight to help her son eventually changed how American health insurance works.

Dorgan told me this story a few weeks ago, when I was working on a piece about the Affordable Care Act’s ban on lifetime limits in health insurance. Next week, as legislators return to their districts for recess and town halls, his advice might prove especially relevant. As David Leonhardt writes for the New York Times, those meetings will be “a chance for people to make clear the actual stakes in the health care debate.”

I initially reached out to the former North Dakota senator because I had heard from a former Senate staffer, John McDonough, that Dorgan was the driving force behind the push to ban lifetime limits. Before the Affordable Care Act, many health insurance plans capped medical benefits at $1 million or $2 million. I wanted to understand how Dorgan became so passionate about ending those caps.

The answer was surprisingly simple: A constituent bothered him about the topic. Repeatedly.

“I used to use her as an example of how to be effective at lobbying Congress,” Dorgan, now a senior policy adviser at law firm Arent Fox, says. “She caught my attention, I cared about it, and it became personal.”

The woman was named Brenda Neubauer. Her son Jack has hemophilia, a blood disease that requires regular injections of an expensive blood clotting agent. The medication cost $30,000 each month.

Jack was in elementary school when he capped out of his dad’s (Neubauer’s ex-husband’s) health plan, which had a $1 million limit. He switched to his mom’s plan, which had a $2 million ceiling. By age 12, he was already halfway through that second policy. Neubauer estimated her son would run out of benefits by time he turned 16.

She started to write letters to the editor in the mid-2000s and attended Dorgan’s events, where she would ask about the issue.

“We formed a relationship,” Neubauer says of Dorgan. “When he would come to Bismarck, he started stopping by my law office. Then I started going to Capitol Hill, and I would bring books and books full of pictures of my son, and we would just meet with anybody we could.”

What made Neubauer effective, Dorgan says, was two things: She was persistent, and she made the issue personal. She would bring along her medical bills, photographs of Jack, and sometimes Jack himself. She was trying to make it clear that there was a tangible problem — one that was affecting her son at that very moment — and that Congress could solve it.

“She stood up at several meetings, and then she came back to DC with her son, who was a high school student,” he says. “She brought sample invoices of the bills they had to pay.”

All of Neubauer’s work made the issue very real to Dorgan. Before that, he hadn’t even known that a lot of insurance plans capped benefits. “I thought if you were insured, you were insured,” he says. Afterward, he became an advocate.

Dorgan’s story is a potent reminder: Citizen input does matter, and it can shape the issues senators choose to prioritize on Capitol Hill.