Through the winter, the families streamed into Portland, bringing stories of violence and persecution in their home countries in central Africa. Portland’s shelter for homeless families soon filled to capacity, so the city put mats on the floor of a Salvation Army gym for 80 more people. Then that, too, wasn’t enough. This month, 250 migrants from Africa arrived in this northeastern city of roughly 67,000 residents in the span of just a week, overflowing the overflow space and forcing Portland to hastily convert a basketball arena into an emergency shelter. Urgent calls went out for interpreters who could speak French, Portuguese and Lingala, a language spoken in the Democratic Republic of Congo. City Council meetings were given over to grappling with how Portland would pay for all of this — and the possibility that still more migrants might be coming.
It is a bit of a mystery in Maine, one of the oldest and whitest states in the country, how Portland has become a focal point for a sudden surge of migrants, mostly from Angola and Congo, who are seeking asylum.
Maine has long wrestled with an aging work force, and some leaders view immigrants as a welcome answer to the state’s struggles to lure younger people to live and work here. Still, the sheer numbers — and the suddenness of the latest arrivals — have opened up a debate about how much Portland should be doing to help immigrants and whether it should entice more of them to come.
“I love the fact that these folks are coming here, and they want a better life, and they’ve chosen Portland,” Jon Jennings, the city manager, said. “But at the same time, I’ve got to figure out how to pay to pave streets and fix sidewalks and all of the things that are uniquely responsible to a municipal government.”
There is friction over the issue, even inside City Hall.
“If we have discovered the magic wand that will bring young families to Portland to help us build the next generation, why would we want to stop that, especially when it costs us so little money?” Ethan Strimling, Portland’s mayor, said.
The migrants arriving in this city have undergone a grueling journey, traveling by air or sea to South America, and then north on foot and by bus to the southern border of the United States, where most of them were arrested by border officials and released with notices to appear in immigration court after they declared their intention to seek asylum.
Nearly 800 migrants from Africa have been apprehended on one stretch of the Texas border and released by authorities since the beginning of October; the surge surprised and puzzled immigration officials, who are more accustomed to seeing Central American families crossing the border. Hundreds of African migrants arrived just this month and were taken to San Antonio, where Catholic Charities provided bus tickets to Portland and other cities that the migrants named as their destinations.
Among Portland’s residents and even some of the families arriving from Africa, it is uncertain how this place became such a draw.
More than 200 asylum seekers are now staying at the Expo, a municipally owned basketball arena in Portland.CreditTristan Spinski for The New York Times
Mr. Strimling, the mayor, has been an outspoken advocate for welcoming immigrants. In April, when President Trump wrote on Twitter that his administration was considering sending detained immigrants to so-called sanctuary cities, Mr. Strimling responded: “If he wants to send more immigrants our way, bring them on.”
But Mr. Jennings, who runs the day-to-day operations of Portland, expressed concern about the costs of aiding everyone, and criticized the mayor for having essentially invited asylum seekers to come here.
Immigrants who are seeking asylum are not permitted to work until at least six months after they file their asylum applications, so Portland has scrambled to provide support. Helped by $400,000 in donations, the city has given emergency assistance to roughly 300 people in recent weeks.
“If you started to see double that or more, I’m not sure how we would be able to handle that,” Mr. Jennings said. “That’s why I think we’ve got to be careful with the messaging and everything that we say publicly.”
Inside the Expo, the basketball arena now filled with 200 cots, families gave varying reasons for choosing Portland, a city that is 81 percent white but that already has a sizable community of immigrants from Africa, including from Congo and Angola. About 13 percent of the city’s population is foreign born, according to census data, many of those residents from Somalia.
Gloire Kikweta, 24, who came from Congo with his wife and two children — the younger of whom was born in Brazil on their way here — said he had left his home because he was being pursued by law enforcement for participating in protests against the former president, Joseph Kabila. He said he did not have a plan of where to go in the United States, but when he was in San Antonio, African immigrants there advised him to go to Portland, telling him that it was an aging city that needed more people, and that it was safe.
Vincent Mbala, 32, who is also from Congo, and came with his wife and three children, said that he learned through internet research that Maine provided financial support for asylum seekers. Maine is unusual in providing general assistance, for up to two years, to immigrants who have valid visas or who have applied for asylum. In most states, asylum seekers rely on local nonprofit groups for aid until they can work, and in many cases struggle to afford housing and food.
Portland also has what local officials believe is the only municipal fund in the country that provides support to asylum seekers before they submit their applications. Called the Community Support Fund, the program was created in 2015 when the Republican former governor, Paul R. LePage, was trying to cut off asylum seekers from the state’s general assistance program. Maine’s new governor, Janet Mills, a Democrat, visited Portland’s shelter in recent weeks and has pledged to help the city financially.
Around Portland, many residents have greeted the migrants enthusiastically. More than 1,200 people have volunteered to help at the Expo. Leaders in the city’s African immigrant community have mobilized people to serve as interpreters and to cook meals for the migrants.
Complaints, too, have come. Some Portland residents said that the city needed to focus more on local needs. The views reflected strains caused by Portland’s recent success in attracting another group — young professionals from other states — whose presence has driven up rents even as it has fueled the local economy.
This year, Mr. Jennings, the city manager, proposed that Portland phase out the municipal fund for asylum seekers. In a recent interview, he said he believed it was one reason migrants were coming here.
Some of the migrants have friends or relatives in Portland. Others said they had heard that the city was welcoming to immigrants.CreditTristan Spinski for The New York Times
The $200,000 fund was already overspent this year by April. The City Council is currently debating whether the fund should be available to anyone who arrives, no matter when, or if it should be limited, given the sudden surge of people.
The city has estimated that it would cost roughly $1.4 million to provide housing vouchers and other support to all the families currently staying at the Expo for a year.
Mr. Strimling, who recently announced he is seeking re-election as mayor, said he wanted to keep the fund open to anyone who needed it. He said that he doubted many migrants were coming to Portland because they had heard about the fund, but that, if they were, it was all the more reason to keep it going.
In East Bayside, a Portland neighborhood where some immigrants have settled in recent years, Roderic Morgan, 74, said the city had enough to deal with in taking care of the homeless population without extending help to asylum seekers. He also expressed concern that there were not enough jobs to go around.
In fact, many businesses in Maine say they struggle to find workers to fill jobs. The unemployment rate in Maine is 3.3 percent, and in the Portland metropolitan region, 2.6 percent. Both are lower than the national rate of 3.6 percent.
Asked how he thought immigrants had changed Portland, Mr. Morgan, a retired newspaper deliveryman, raised a different issue.
“It’s not just the immigrants that have invaded Portland,” he said. Well-off people from other places were moving to Portland and making the city unaffordable, he said.
In Parkside, not far from the Expo, Timothy Goldkin, 29, called it a “beautiful thing” to have more diversity in Maine. Mr. Goldkin, who has a housemate who is an asylum seeker, said he would rather have more immigrants in Portland than wealthy people migrating from other states and changing the city’s landscape and culture.
“I’m much more worried about the people with lots of money who want to just completely make it their town, with zero regard to what it was,” he said, “than the folks who are fleeing persecution and in fear of their life and who are coming here to try to understand our culture and integrate into it, while still holding onto and bringing some of their own loveliness.”
For now, a major challenge for the city is to find permanent housing for the scores of families staying at the Expo and another shelter. Neighboring cities have agreed to help identify vacancies, and Mr. Jennings said that a lumber company in Jackman, three hours north of Portland, had reached out with an offer to house some of the families in Jackman if they were interested in working for the company.
“I’ve had people all over the state inquire about whether some of these folks could come to other parts of the state, because they need qualified workers,” Mr. Jennings said. “They need new people