On Wednesday afternoon, Kris Kobach, the vice chair of President Trump’s Presidential Advisory Commission on Election Integrity and Kansas secretary of state, told MSNBC’s Katy Tur that he thinks “we may never know” whether or not Hillary Clinton won the popular vote in the 2016 presidential election.

Tur had asked Kobach to address arguments that the commission was set up simply to verify Trump’s belief that he won the popular vote over Clinton, who in reality won the popular vote by close to 3 million votes (though Trump won the Electoral College). Kobach denied this, saying the commission was “look[ing] at facts as they are.” To be clear: According to election experts, voter fraud is extremely rare and does not sway national elections.

Tur then asked Kobach if he thinks there’s a possibility that Clinton didn’t win the popular vote, to which he responded, “We may never know the answer to that question.”

.@KatyTurNBC: 'You think that maybe Hillary Clinton did not win the popular vote?"Kobach: 'We may never know' https://t.co/FC26JcqrRD — MSNBC (@MSNBC) July 19, 2017

Kobach’s comments come amid calls from top Democrats for him to step down from the committee. On Tuesday, more than 70 lawmakers signed a letter asking for Kobach to withdraw his request for voter information last month. His latest remarks on the popular vote are likely to ignite further ire from Democrat leaders, and add to the ongoing controversy surrounding Trump’s “voter fraud squad,” which had its first official meeting on Wednesday.

As vice chair of the committee, Kobach has defended some of Trump’s most outrageous, erroneous claims: for example, that 3 million to 5 million people voted illegally in the 2016 election, costing Trump the popular vote. In an interview with NPR last month, Kobach pushed back against the idea the commission was founded to confirm Trump’s unfounded theory.