When New York City launched the nation's biggest municipal ID card program last year, advocates said it would help people living in the U.S. illegally to venture out of the shadows.

But since Donald Trump was elected president, city officials are instead fielding questions about whether the cards could put those same people at greater risk of being deported.

The city has vowed to protect cardholders' personal records and might even delete them using a kind of self-destruct provision that allows for the information to be destroyed at the end of the year.

At least one state lawmaker has criticized that idea, saying it could make it impossible to trace people if they have obtained cards fraudulently.

Some immigrants take comfort in the city's stance, while acknowledging they are still wary.

Alberto Saldivia got his "IDNYC" card this year after spending 15 years in the country without legal authorization.

"It did cause me considerable concern, because they have my information, also the information of my son," the 53-year-old Mexico native said through an interpreter.

But he felt reassured when Mayor Bill de Blasio said last week that the city would "absolutely" safeguard cardholders' identities. De Blasio, a Democrat, said officials would assess whether to delete the personal records, a provision that was built into the program partly over concerns about the possible election of a Republican president such as Trump, whose campaign promises included a vow to deport millions of people in the U.S. illegally.

Municipal ID programs began in 2007 in New Haven, Conn., and have expanded to about 10 cities, including Los Angeles and San Francisco. New York's program is the most ambitious, with more than 800,000 cardholders, many of them U.S. citizens or legal residents.

Officials encouraged everyone in the city to sign up, but the program was aimed at those without other forms of ID, including homeless people and, especially, the estimated 500,000 immigrants living illegally in the city. The ID would help them do such everyday things as cash a check or attend a parent-teacher conference at a public school, advocates said.

The program quickly proved popular, with New Yorkers waiting hours in line and months for appointments to register early on. Pope Francis received a ceremonial one during his visit to the city last year, and United Nations Secretary General Ban Ki-moon said the card would make him "a real New Yorker."

But civil liberties advocates sounded alarms about the city collecting identity documents that immigration authorities or law enforcement could request, with a judge's approval.

The program's backers included language that allows for destroying the applicants' identity and residency information at the end of 2016 if administrators do not move to keep them.

"Protecting it from a possible Republican president was just one of the reasons" for the provision, said City Councilman Carlos Menchaca, who wrote the law that created the program.

A critic of the program said deleting the records would only compound concerns about it.

"It's completely irresponsible to destroy the documentation of people who applied for a government-issued ID card," said state Assemblywoman Nicole Malliotakis, a Republican.

She said the proof-of-identity requirements may not be stringent enough to prevent fraud, and deleting the records would leave authorities "no way of knowing who these people are, how they obtained this documentation."

Some immigrants and their advocates remain hopeful that the IDs won't backfire. The extent of the program should thwart using it to target immigrants here illegally, since they represent only some of the cardholders, said Javier Valdes of Make the Road New York, an advocacy group that pushed for the program.

Juan Rosas Carrera plans to keep his appointment this weekend to get an IDNYC card, despite a friend's warning that it could be risky to give authorities his name and address. Rosas Carrera, a Mexican national and construction worker, has been living in the U.S. illegally for 17 years.

Still, he wants an ID card to open a bank account and feels it's worth the worry.

"I feel safe in New York. I also think that if you don't have a criminal record, nothing bad will really happen," said Rosas Carrera, 48. "But I am a bit worried about Trump."