The call from the White House came late in the week. Rep. Paul Ryan was vowing to slash Medicaid in his 2012 budget proposal, the administration strategists explained, and they wanted to have a powerful response ready, complete with poignant stories of Americans who might lose their health coverage under the Republican plan.

Within minutes, Elizabeth Prescott was on the case. The coordinator of a vast database of real-life stories maintained by the advocacy group Families USA, Prescott worked through the weekend poring over hundreds of files. Among them were heart-wrenching tales of hardship faced by people whose care is dependent on Medicaid, the joint federal-state health insurance program for the poor and disabled.

By the next Monday morning, Prescott was ready to e-mail the White House the first batch of five people from five different states. But Prescott needed more, so she set to work calling smaller health-care advocacy and legal aid groups across the country in search of as many compelling cases as possible to counter the chairman of the House Budget Committee.

With Republicans determined to disrupt implementation of the new health-care law and promote their own fixes to Medicaid and Medicare, and Democrats hopeful of swaying a stubbornly divided public to embrace the law as it takes effect between now and 2014, no one expects the fight to let up anytime soon. And for Democrats and supporters of the law, the weapon of choice is the compelling individual story, a tool honed by former President Ronald Reagan that has been archived and analyzed, computerized and systematized to new levels for this battle.

“When it comes to health-care issues, individual stories are even more powerful than usual because people worry about possible illnesses in their own family,” said Robert Blendon, a polling analyst with the Harvard School of Public Health. “When they hear about something that has gone wrong for someone else, it’s not an abstract policy issue. It’s something that could happen in their own lives.”

Republicans and other opponents of the health-care overhaul also strive to put a human face on their arguments. During the health-care debate, they ran a television ad featuring a Canadian critiquing her country’s government-run health system. And now that they control the House of Representatives, Republicans have tapped business groups hostile to the law to provide a steady stream of employers to testify at hearings about the burdens the law might impose on them.

Still it’s the Democrats and other supporters of the law who have made the personal narrative a centerpiece of their political strategy by relentlessly publicizing the cases of ordinary Americans who stand to lose if the law is modified or repealed. Democratic members of Congress routinely cite such constituents by name in speeches and news conferences on the issue. The White House’s Web site features a clickable map of video testimonials titled “50 states 50 stories” and asks viewers to share their accounts on the theme “How is the Affordable Care Act helping you?”

All of which makes Prescott, a 25-year-old who spends most of her time making phone calls from a small, spartan office in her organization’s Washington headquarters, one of the busiest foot soldiers in a public relations battle that remains as heated as when the health-care law was adopted a year ago.

Families USA is hardly the only group that specializes in finding individual cases. With the group’s encouragement, smaller, locally based allies are increasingly maintaining lists of their own. The White House has unique sources as well — drawing, for instance, on those people who have written President Obama directly.

Still, for sheer scope and geographic reach, few can match the Families USA story bank. Begun about two decades ago in the lead-up to then-President Bill Clinton’s failed effort at health reform, it has expanded to include thousands of names in a detailed, confidential database that can be searched according to such fields as health issue, location, race and income. It even includes notes about how articulately the person describes their experience.

As often as five times a day, Prescott consults the system in search of a case to match the latest request. She helped Democratic congressional staff members find witnesses for a recent Senate hearing spotlighting early beneficiaries of the health-care law. And when a reporter for the Bismarck Tribune in North Dakota needed a local example, it was Prescott who connected her with the perfect case: a photogenic 16-year-old student at Bismarck High with hemophilia who no longer has to worry about lifetime caps on his father’s health plan.

Since joining Families USA three years ago, Prescott, who sports a chic blond bob and wire-rim glasses, has done little to alleviate the generic carpeting and bland furniture in her office. No personal photos adorn the walls; barely any knickknacks clutter her desk.

Yet her voice exuded warmth during a recent phone call to Sharon McKinney, an office manager in Knoxville, Tenn., whose husband, Ron McKinney, received home nursing care through Medicaid before his death in 2008 from amyotrophic lateral sclerosis, often referred to as Lou Gehrig’s disease.

“Do you feel like that helped with his health?” Prescott gently asked.

“It was the best thing that could have happened for him,” said McKinney, 61, noting that her salary was insufficient to cover the cost and that the couple had exhausted the $1 million lifetime cap on their health insurance plan. “Yes, Ron was unable to move or even breathe on his own. But he still felt he had the best quality of life he could have had because he could be at home, with his family.”

After about 20 minutes, Prescott had heard enough to make up her mind.

“I would really like to tell the White House about your case,” she told McKinney. “Would that be all right?”

“Oh, please do. If I could help just one person to have what Ron was able to have . . .” McKinney choked up for a moment. “Well, it would be such a blessing.”

Prescott blinked back tears. Sometimes, colleagues say, she has to take a break after hearing an account that is particularly sad.

But as she hung up and began transferring her notes into the database, Prescott merely gave a sorrowful smile.

“I think she’ll make a great spokesperson,” she said. “She was so concise and eloquent about the difference Medicaid made for her and her husband. I didn’t have to pull it out of her at all.”