Housing Secretary Jack Kemp, once a champion of "trickle-down" economics, spent the night in a housing project as part of President Bush's mission to take "inventory" of the nation's homeless and impoverished.

Kemp toured housing alternatives for the poor and homeless Thursday and slept at the Opportunity Towers, a federally supported apartment complex for senior citizens and the handicapped."We wanted Kemp to see human faces," said Robert M. Hayes, a lawyer for the Coalition for the Homeless who accompanied the new housing secretary. "Ten minutes on a steam grate is worth 50 white papers."

"I hope this touches his heart," Hayes said, "but in any event, his political future will be linked with his success in battling homelessness."

Kemp, a former Republican congressman from New York who is closely identified with conservative "supply-side" economic theory, was accompanied on his tour by Pennsylvania's U.S. senators, Republicans John Heinz and Arlen Specter.

At the Women of Hope, a permanent shelter for impoverished women, most of whom are mentally ill, the three listened as about 16 residents complained about the lack of affordable housing and jobs for unskilled workers.

"While we sit here in this room tonight, many of our sisters and brothers are out in the freezing cold," said Sister Mary Scullion, the Roman Catholic nun who runs the Women of Hope.

Philadelphia, the nation's fifth largest city, has a homeless population estimated at 10,000.

Sister Scullion told Kemp that more federal emphasis and money are needed to lift the burden of the homeless from cities and to provide more affordable housing for low-income citizens.

"We want you to go tour and to talk, but more importantly . . . the answer to helping is what happens when you go back to Washington," she said.

Kemp told reporters he had come to Philadelphia "to talk with folks and to listen, to learn about the problems, to see what they've done and what I can do to be a catalyst, to make an impact, make a difference in this problem."

"It's a very human, real problem that exists and it's a national tragedy, and George Bush wants me to not only inventory the problem but inventory some of the answers," said Kemp, who plans to visit other cities to examine their housing problems.

Hayes, who is acting as a tour guide, called Kemp's visit "a non-ideological, novice's composite tour" with as little time as possible spent in offices with politicians.

Kemp, Heinz and Specter stopped at a city-run shelter for homeless men, where most of the approximately 75 men sitting in plastic chairs seemed more concerned with getting a bed than talking to political leaders.

"It's hard to get in here, man," said Nathaniel White, 42. "They call your name once - if you don't hear your name called, forget it."

Earlier in the day, Kemp visited a soup kitchen and a homeless shelter in Baltimore. At the Viva House shelter, he told residents that he came as an advocate for their needs, not as an adversary.

"We want to make some changes," he said.