Foreshadowing a theme that Pope Francis is expected to trumpet on his forthcoming visit here, Philadelphia Archbishop Charles J. Chaput waded into the nation's fierce debate on immigration Tuesday.

He outlined the social costs of a "flawed immigration system." He reprised a Christian's obligation "to protect migrant families."

The address he titled "Sanity, Indifference, and the American Immigration Debate" took a poke at Republican White House candidate Donald Trump.

"At least one of our presidential candidates has already made the national immigration debate ugly with a great deal of belligerent bombast," he told participants at a three-hour panel discussion that drew about 130 people to the archdiocesan pastoral center in Center City.

"His success in the polls shows that many people - including many good people - are very uneasy about the direction of our country," Chaput said.

Speaking in a hall lined with portraits of former Philadelphia archbishops, a carving of Jesus on the cross, and a poster of Francis promoting the World Meeting of Families this month, Chaput reminded attendees of the pope's "special sympathy for migrants and refugees," and disdain for treating them as part of a "throwaway culture."

Citing Central America, he spoke of the poverty and violence that separate families by forcing parents to leave in search of work, and children to be sent away "to escape the bloodshed of organized criminal networks."

He said "many nations, including our own, have immigration policies that weaken, rather than strengthen, the family." He offered suggestions to overhaul the system, calling for:

"A legalization program that gives undocumented persons an honest, attainable chance at citizenship."

Preservation of "birthright citizenship," enshrined in the 14th Amendment, which grants American citizenship to anyone born on U.S. soil regardless of the mother's immigration status.

Dismantling the nation's three family detention centers, including one in Pennsylvania, where immigrant mothers and their minor children are incarcerated pending deportation proceedings. "The practice is needless and inhumane," he said. Some activists hope the pope will call for closing the centers in his U.S. visit.

Retaining family reunification as the cornerstone of U.S immigration policy instead of shifting to an economic model that would emphasize a person's skills and advanced education over family ties.

Lowering the record rate of deportations, roughly 2.6 million people since 2008. "This brutally affects immigrant families, especially those with children who are U.S. citizens," Chaput said. "Do we really want to invest in young U.S. citizens - the future leaders of our nation - by deporting their parents?"

Responding to a question from the audience, Chaput said, "I hope the pope, when he speaks, brings our country to a climate of change." That, he added, almost parenthetically, might take a miracle in a presidential election year.

Two panels - on caring for immigrant families, and strategies for keeping them together - consisted of Catholic sisters, immigration activists, immigration lawyers, and municipal officials.

Sister Linda Lukiewski of Holy Innocents Parish, St. Joan of Arc Community, spoke about her group's advocacy and accompaniment of newly arrived immigrants, and the challenges when parishioners set in their ways meet foreign-born newcomers.

Peter Pedemonti, director of the New Sanctuary Movement of Philadelphia, a multi-faith immigrant support group, praised the courage of a Honduran woman who faced a final order of deportation last year, went into sanctuary at a local church, and ultimately prevailed, winning an administrative stay. He cited the story of the Red Sea parting in Exodus: "The water only parted when the first person stepped into it. That was God and the people acting together."

Rosa Murcia-Garcia, an administrative assistant at the Sisters of St. Joseph Welcome Center in Kensington, recounted the challenges she faced when she came, undocumented, from Guatemala with her husband and two children in 2008. Today she is a U.S. citizen.

Jennifer Rodriguez, executive director of Mayor Nutter's Office of Immigrant and Multicultural Affairs, presented a slide of immigration trends in the United States that showed a high point around 1910, a low point around 1970, and resurgence now to the 1910 level.

For inspiration, she quoted Francis, from his proclamation on evangelization two years ago but relevant today in the context of immigration:

"How beautiful [are] those cities which overcome paralyzing mistrust, integrate those who are different, and make this very integration a new factor of development!"