The first wave of applicants for Chicago’s new CityKey municipal identification card included an elderly parolee from prison, Puerto Rican evacuees who lost personal documents in Hurricane Maria and an undocumented university student who needed official paperwork to get a job.

With CityKey, the administration of Mayor Rahm Emanuel has embarked on an experiment that officials sell as a kind of welcome mat for many residents who lack access to public and even private services without proper identification. At the same time, however, some conservatives complain the new ID could be used to facilitate voter fraud.

So what exactly is CityKey, and what isn’t it?

“Without a government-issued ID, residents can’t enter a school building to pick up their child, pick up packages or a prescription, things many of us take for granted,” said Kate LeFurgy, a spokesperson for the city clerk’s office, which is administering the CityKey initiative, budgeted so far at $2 million.

Despite attacks from the political right, the concept behind CityKey isn’t unique to Chicago.

Advocates have been pushing for it here since the first municipal ID program launched in New Haven, Conn. in 2007. Then, in 2015, New York City launched the largest municipal ID program in the nation with in excess of 1 million card applications. That has led other cities, Chicago included, to follow suit.

Using the New York program as a model, Emanuel in 2015 formed a task force to explore a municipal ID for Chicago.

Members of the task force, which included dozens of community organizations, said they pinpointed several barriers that some Chicago residents face in obtaining a government-issued ID. Among those affected, the task force concluded, are not just the undocumented but also refugees, domestic violence survivors, transgender people, the formerly incarcerated, the homeless, and senior citizens.

“What we did in crafting the municipal ID program was to be sensitive to how these individuals in these sectors prove who they are and prove they are residents even if other kinds of identification documents aren’t available to them,” said Fred Tsao, senior policy counsel for the Illinois Coalition for Immigrant and Refugee Rights, one of the groups that helped implement the card in Chicago.

The CityKey application requires proof of identity and proof of residency, but the bar is set lower than what is needed to obtain an official state identification card. Applicants for the state document, for instance, must provide a Social Security number.

Illinois law does allow undocumented immigrants to obtain a driving permit, but the so-called temporary visitor driver’s license explicitly states it is not valid as a form of identification.

What’s more, in launching CityKey, Chicago has decided not to keep any of the information provided by residents used to obtain the card. That may be a reaction to the experience in New York, which initially did retain those records but then gained court approval to destroy them following President Donald Trump’s crackdown on undocumented immigrants.

In Chicago, the clerk’s office is only keeping track of the date the card was issued, the date it expires and its unique identification number. This has alleviated concerns in the immigrant community, particularly among those without legal status, about whether their information would be stored, shared or ultimately used against them.

“Many of the immigrants already saw the benefit to the card but may have had some reluctance to signing up because of those concerns of retention,” Tsao said. “But now that those protections are in place, those concerns are no longer in place.”

Since then, the response among immigrants has been “enthusiastic,” Tsao said.

Now billed as a “3-in-1 card” available to all Chicagoans, CityKey cards can link with Chicago Public Library and Chicago Transit Authority riders’ Ventra accounts. CityKey does not have the debit function that Ventra cards once had because that would require information to be stored, according to the clerk’s office. Instead, the city is trying to work with banks so that residents can use a CityKey card to open a checking account.

In addition to being recognized by city government, the cards also offer some benefits and discounts at approximately 30 businesses, sporting events and cultural institutions, including one free day at the Field Museum, 10 percent off select tickets at the Joffrey Ballet and $2 off admission to the Chicago Children’s Museum. Residents will soon be able to get discounts on prescription drugs as well, according to the clerk’s office.

The first 100,000 cards issued will be free and then they will cost $10 for adults and $5 for minors, though fee waivers will be available. They will also be free for senior citizens.

Controversy over the cards began even before any were distributed. Political conservatives, including then-GOP candidate for governor Jeanne Ives, claimed early this year that CityKey could lead to voter fraud because the card would be considered a valid form of identification for voter registration.

That theme was then amplified by Fox News talk-show host Tucker Carlson, who declared that Chicago was “abetting voter fraud” by allowing undocumented immigrants to use the card.

But experts say voter fraud in modern day elections in the U.S. is almost non-existent. Indeed, the Brennan Center for Justice at the New York University University School of Law has conducted extensive research on claims of widespread voter fraud and dismissed them as a “myth.”

“Examination after examination of voter fraud claims reveal fraud is very rare, voter impersonation is nearly non-existent, and much of the problems associated with alleged fraud relates to unintentional mistakes by voters or election administrators,” according to the Center’s website.

Carlson’s assertions come amid a larger push among conservatives for stricter voting laws. The Republican Party has strengthened its stance in recent years by supporting legislation that would not only require a photo ID while voting but also proof of citizenship. Similarly, the GOP has been advocating for a national identification card available only to U.S. citizens and legal residents to be used for employment and voting purposes.

The CityKey card is allowed for voter registration because both state and federal election laws require election authorities to accept all government-issued IDs when citizens register to vote, according to the Chicago Board of Election.

But aside from government-issued IDs, there are numerous other documents that people can use to register to prove their identity and their address. Among them: a debit or credit card, a lease, a student ID, an insurance card, a union membership card, a Firearm Owners Identification card, a utility bill, a medical bill, a bank statement, a pay stub, a school report card and mail from a government agency.

The CityKey card, therefore, is “just another form of ID,” said Cook County Clerk David Orr.

Orr and other experts do not believe access to a municipal ID will lead to widespread voter fraud. People do not have to prove their citizenship when they register to vote, but they do have to attest to it and sign their name affirming that it is true, otherwise risking fines, imprisonment or deportation.

“The last thing a non-citizen wants to do is to get trapped into a situation of voting because they get deported,” Orr said. “Anybody that knows the immigrant community, and from the research that we’ve done, if someone registers and they’re a non-citizen, it’s by mistake.”