President Trump, accompanied by Vice President Pence, right, and Kansas Secretary of State Kris Kobach, center left, speaks in July at the first meeting of the Presidential Advisory Commission on Election Integrity. (Jabin Botsford/The Washington Post)

Federal judges questioned Tuesday whether privacy advocates have the right to sue President Trump's election-integrity commission to try to block its planned collection of millions of voter records.

A three-judge panel of the U.S. Court of Appeals for the D.C. Circuit seemed skeptical of the specific harm to a privacy watchdog group trying to protect voter data the commission is seeking from 50 states and the District, including individual birth dates, political affiliations and partial Social Security numbers.

Judge Stephen F. Williams asserted that the commission's powers appeared limited to requesting — not demanding — the information from states and said its "potency seems very low."

Judge Douglas H. Ginsburg suggested the commission would have access only to publicly available voter data.

"Isn't this information already public?" he asked the attorney for the Electronic Privacy Information Center (EPIC).

The Presidential Advisory Commission on Election Integrity — led by Vice President Pence and Kansas Secretary of State Kris Kobach (R) — was created in May to investigate unsubstantiated claims of widespread voter fraud that Trump has said cost him the popular vote in 2016.

In June, the commission asked state election officials to hand over information from voter registration files. More than a dozen states, including Maryland and Virginia, have partially or entirely rejected the commission's request, because of concerns about data breaches and state laws limiting disclosures.

The lawsuit at issue Tuesday was filed by the privacy group EPIC and is one of several challenging the commission's work, citing concerns about the government's ability to safeguard the sensitive data and about how the information will be used. Three others are pending in court in Washington. Some election experts and voting rights groups worry the commission would use the information to purge voter rolls and suppress participation.

In court Tuesday, EPIC Executive Director Marc Rotenberg called the sweeping nationwide data collection "absolutely unprecedented" and said the organization is "in the dark" about how the data would be stored and who would have access to it.

The organization says the commission should have conducted and published the results of a privacy protection review required by law.

"EPIC has a critical role in protecting the privacy of this information, and that's only possible if we have access to this report," Rotenberg said after the hearing.

In court filings, the Justice Department said that the commission is "only collecting voter information that is already publicly available under the laws of the states where the information resides" and that responding to the request was voluntary.

The challenge from the watchdog group relies on a 2002 law designed to protect the privacy of individuals whose data might be collected by the government and that EPIC says requires "transparency" and "accountability."

But Justice Department lawyer Daniel Tenny said Tuesday that the measure does not apply, because the election-integrity commission is a "classic advisory commission" and not a federal agency with independent authority.

"Federal advisory committees have never been thought to fall within the definition of 'agency,' and the commission in this case exists solely to provide advice to the president and exercises no independent authority," according to the Justice Department filing.

After the commission's initial request, the White House clarified it had scrapped plans to use a Pentagon-operated website to accept the data and had designed a system inside the White House to take the submissions.

The appeal to the D.C. Circuit came after a federal judge in July said the commission could go forward in requesting voter data. U.S. District Judge Colleen Kollar-Kotelly concluded the watchdog group had the right to sue under the law for a privacy review but said that because the commission was a presidential advisory panel — and not a federal agency — the privacy law did not apply.

"The mere increased risk of disclosure stemming from the collection and eventual, anonymized disclosure of already publicly available voter roll information is insufficient" to block the data request, Kollar-Kotelly wrote.

The third judge on the D.C. Circuit panel Tuesday was Judge Karen LeCraft Henderson.

Spencer S. Hsu contributed to this report.