Kansas Secretary of State Kris Kobach, center, at a meeting of the Presidential Advisory Commission on Election Integrity on Tuesday in Manchester, N.H. (Holly Ramer/AP)

President Trump's "election integrity" commission, a source of roiling controversy since its inception, convened here Tuesday amid fresh discord over an unfounded assertion by its vice chairman that the result of New Hampshire's Senate election last year "likely" changed because of voter fraud.

Kansas Secretary of State Kris Kobach (R) largely defended an article published Friday in which he pointed to statistics showing that more than 6,000 people had voted in a close election here using out-of-state driver's licenses to prove their identity. He suggested that was evidence of people taking advantage of New Hampshire's same-day registration and heading to the Granite State to cast fraudulent votes.

New Hampshire only requires voters to state their “domicile,” a looser standard than residency, and college students and others routinely vote without state-issued driver’s licenses.

Kobach's article has been rebuked by election experts and among those who criticized his argument was New Hampshire Secretary of State Bill Gardner (D), a fellow commission member and host of Tuesday's meeting of the Presidential Advisory Commission on Election Integrity. After an organizational gathering in July, the panel is holding several meetings around the country.

Gardner said the distinction between residency and domicile requirements is complicated and is one that his state is working on. But Gardner defended the Senate election result as “real and valid” and said Kobach’s article — which appeared in Breitbart, the publication led by Stephen K. Bannon, the recently ousted White House chief strategist — showed why the commission needs to be more careful about its assertions moving forward.

Gardner noted that Kobach said at the previous meeting there should be no “preordained” or “preconceived” notions about what the group will conclude after studying data and hearing from experts.

“That is something that we all need to stay focused on,” Gardner said. “I hope we all learn from this.”

Another Democrat on the commission, Maine Secretary of State Matthew Dunlap, called Kobach’s Breitbart piece “reckless” and said he shouldn’t be comparing requirements for voting and obtaining driver’s licenses. Doing so, he said, is “almost as absurd as saying if you have cash in your wallet that’s proof that you robbed a bank.”

Kobach told fellow commissioners Tuesday that he was still wrestling over his word choices and conceded there was no way to know for certain whether Democrat Maggie Hassan’s election to the Senate was illegitimate. She prevailed in November by 1,017 votes.

“It’s a very difficult issue to condense into a short article,” Kobach said of his Breitbart piece.

The commission — which heard several hours of testimony Tuesday about voting trends, allegations of voter fraud and ways to manipulate electronic voting machines — was spawned from Trump’s baseless claim that illegal voting cost him the popular vote in the November presidential election against Democrat Hillary Clinton.

Trump named Vice President Pence as chairman, but he has largely ceded leadership of the commission to Kobach, who has pursued cases of voter fraud in Kansas and is now running for governor.

Democrats in Washington have derided the commission as a waste of resources targeting a problem that is not remotely as prevalent as Trump has suggested.

During a floor speech in the Senate on Tuesday, Minority Leader Charles E. Schumer (D-N.Y.) called the commission "a punishment in search of a transgression that never happened" and said its real purpose is to tamp down Democratic turnout in the future.

The commission faced widespread pushback from an initial request to states to obtain voter information, including from some Republican officials, who questioned its reach. And a federal judge last month tore into the commission for reneging on a promise to fully disclose public documents before its first public meeting.

Democratic senators have also voiced frustration that the commission has not responded to requests for information from lawmakers with oversight responsibilities. A letter Tuesday from Sens. Amy Klobuchar (D-Minn.) and Sheldon Whitehouse (D- R.I.) accused the commission of "failing to comply with standards set forth by the laws that govern presidential advisory commissions."

The latest controversy over Kobach’s article emerged days before the scheduled meeting here at the New Hampshire Institute of Politics at Saint Anselm College.

In a statement issued Tuesday before the meeting, Sen. Jeanne Shaheen (D-N.H.) chastised Kobach for using “deceptive and irrelevant data to rehash the same false claims that have been debunked time and time again by independent analysis and by members of both parties in the Granite State.”

"Granite Staters are not gullible or naive, and we do not appreciate those who impugn the integrity of our state's voting systems based on unsubstantiated accusations," she wrote.

Since Friday, Gardner — one of five Democrats on the 12-member commission — has faced calls to resign from the commission from fellow Democrats, including Shaheen.

At the outset of Tuesday’s meeting, he said he considered it his civic duty to continue serving.

“New Hampshire people are not accustomed to walking away or stepping down from their civic duty, and I will not either,” Gardner said.

Alan King, another Democrat on the commission, missed Tuesday’s meeting, citing a conflict. In a phone interview, King, a probate judge in Alabama, said he told Pence’s staff that he would be unavailable for three days in September, including Tuesday.

“They’ve known this since July,” King said. “But I get it. I’m just one person.”

King, who has voiced strong skepticism about Trump’s voter fraud claims, said he had heard a lot of “pushback” about his service on the commission but plans to continue participating “as of right now.”

“As long as I believe I have a voice for truth I plan to continue to serve,” he said. “But I have a serious question about whether differing views are welcome.”

More than a dozen invited witnesses addressed the commission on Tuesday, including John Lott, an independent researcher and Fox News commentator, who argued that a background check system for gun purchases, could be used to screen new voters.

Lott said that the National Instant Criminal Background Check System (NICS) flags many of the same concerns that could disqualify voters. Democrats have praised the system, he said, and Republicans are eager to have tighter controls against voter fraud.

“It might be a solution that might please both sides,” Lott said.

Hans von Spakovsky, a senior legal fellow at the Heritage Foundation, also made a presentation to his fellow commissioners, detailing a database that he said showed 1,071 proven incidents of election fraud.

The value of the database has been disputed by the Brennan Center for Justice, a New York-based law and policy institute, which said in a recent analysis that it "substantially inflates and exaggerates the occurrence of voter fraud" and that most cases are more than five years old.

Commission members were greeted here Tuesday morning by several dozen protesters holding signs and chanting, "Hey, hey, ho, ho, Trump's sham commission has got to go."

Among those to address the group outside the college was Jason Kander, the former secretary of state of Missouri.

"This commission was formed to justify the biggest lie a sitting president has ever told," Kander said. "They should be ashamed of themselves."