WASHINGTON, D.C. - If your state, city, or county recently adopted a 10-year plan to end chronic homelessness, Philip Mangano probably had something to do with it.

For two decades, Mangano tried to convince government officials to help homeless people. “Our hearts and bodies ache,” he once told an audience of homeless advocates, in a paraphrase of the abolitionist Harriet Tubman. “We are tired of homelessness and all of us here are called to abolish it.”

Four years ago, he became one of those officials, and now, even with limited funding, he’s doing all he can to carry out that mission.

Inspired by the work of St. Francis of Assisi, who renounced a life of wealth and privilege for poverty and spiritual service, Mangano quit his job as an agent in the music business 25 years ago to volunteer full-time on the St. Anthony’s breadline in downtown Boston. His work with the homeless eventually led him to help found the Massachusetts Housing and Shelter Alliance, where he spent 12 years as the executive director.

In 2002, Mangano joined the administration of President George W. Bush as the executive director of the federal Interagency Council on Homelessness (ICH). At the time, the council was an underfunded and almost forgotten cog in the federal machinery, with just $35 million in funding from the departments of Housing and Urban Development, Health and Human Services, and Veterans Affairs.

In most areas, $35 million is barely enough to cover the cost to rehab 350 apartments, let alone tackle a nationwide goal like ending chronic homelessness. Worse, many critical programs for housing poor people, such as Sec. 8 vouchers, have come under attack in the federal budget, and continue to be underfunded.

Still, Mangano has had some success. A year after his appointment, Bush made ending chronic homelessness one of his administration’s few stated housing goals.

Helping the chronically homeless means targeting the people that spend years on the streets. On any given night, they may represent just a few of the people that fill city parks or homeless shelters. However, they come back night after night, they often suffer from multiple serious problems, such as mental illness or substance abuse or AIDS, and many need expensive help. In Portland, Ore., 35 homeless people rang up an average of $42,075 each per year in health care and incarceration costs, according to local officials. But the cost of placing these 35 people into permanent housing with intensive services turned out to be just $25,776 per person per year, including the cost of health care and resolving their run-ins, if any, with the law.

Advocates for the homeless have for several years been pushing to get the resources to build new “supportive housing” apartments like the ones in Portland. Supportive housing gives chronically homeless people a stable, safe place to live and then offers them services ranging from drug treatment to mental health counseling.

Now those advocates have Mangano on their side. Armed with PowerPoint presentations, sharp suits, and the tools of cost/benefits analysis, Mangano has spread the ideas behind supportive housing to local officials across the country.

“I believe very ardently in stealing the best ideas,” Mangano said. “It’s insane that something should be working in Philadelphia and not be heard of in Seattle ‘til five years later.”

At his urging, more than 286 city mayors and county executives have drawn up their own plans to end chronic homelessness within 10 years. Every U.S. state or territory, except Wyoming, has started an interagency council on homelessness modeled on the federal council and designed to bring together all the officials in that state who deal with homelessness.

With relatively little new money on the table, these officials are focusing the resources they already have on supportive housing, from Sec. 8 “housing choice” vouchers to Community Development Block Grants. Many states, including Connecticut and Massachusetts, now give supportive housing projects an advantage in the competition for federal low-income housing tax credits.

This integration of resources is “one of the things the Bush administration has done a good job on,” according to housing guru Henry Cisneros, former head of HUD under President Clinton.

Thanks to these integrated resources, the plans to end homelessness are already beginning to work: More than 35,000 chronically homeless people have found homes in supportive housing developments since 2003, according to Mangano, who now counts 30 cities where the number of chronically homeless people is already shrinking.