Since the year 2000, Kansas Secretary of State Kris Kobach (R) has found 129 noncitizens who either successfully or attempted to register to vote in his state. Thats virtually nothing compared to the millions of votes cast in Kansas over the last two decades and the 1.8 million voters currently registered there.

Kobach likes to call those 129 cases just the tip of the iceberg. Its a remarkably powerful metaphor a way to pivot around a seemingly insignificant statistic and instead draw concern from the uncertainty of what we dont know. Its the kind of thinking he used in 2011 to persuade Kansas lawmakers to pass a law requiring people to bring a document proving their citizenship when they go to register to vote.

Over the course of an eight-day trial this month, Kobach had the floor in a Kansas City federal courtroom to show just how deep that iceberg was. The American Civil Liberties Union is suing him over the Secure And Fair Elections Act, or SAFE Act. The civil rights group says that it is needlessly restrictive and has impacted 35,000 voters. To uphold the Kansas statute, the 10th U.S. Circuit Court of Appeals told Kobach he had to show that noncitizen voter registration was a widespread issue and that nothing short of Kansas proof of citizenship law could stop the problem.

As the trial progressed, it became clear that the case was about much more than the Kansas law and Kobach. It began to revolve around a deeper question: Is the evidence that supports the idea of widespread voter fraud credible at all? For the ACLU, the trial offered a unique chance to get a judge to assess the reliability of experts whose research is used to justify claims about voter fraud across the country; even though several studies and investigations have shown it is not a widespread problem .

The ACLU repeatedly got Kobachs experts to concede their work was not always subject to peer review and highlighted flaws in their methodology. In doing so, the ACLU sought to deal a more devastating blow to claims about voter fraud, creating a court record anyone can point to in the future to question claims about illegal voting.

The most tense moments of the trial came when ACLU cross-examined the experts whose research Kobach relied on to say noncitizen voter registration was a substantial problem. One of those witnesses was Jesse Richman, a political science professor at Old Dominion University, who did an analysis of Kansas voter registration that showed as many as 18,000 noncitizens could be on the rolls in Kansas. Kobach has also relied on Richmans work to estimate that more than 3 million noncitizens could have voted in the 2016 election, a figure that would be greater than presidential candidate Hillary Clintons margin of victory in the popular vote. President Donald Trump has said he believes he only lost the popular vote because of illegal votes.

But when Richman was on the stand, Dale Ho, the director of the ACLUs voting rights project, got him to concede that he did not believe noncitizens voting changed the outcome of the popular vote . It was a significant victory for the ACLU because it provided an unequivocal challenge to the basis of Trump and Kobachs claims about voter fraud.

Ho also questioned Richmans methodology and led him into a trap. When Richman was looking at Kansas voter roll data and DMV records to identify potential noncitizens, one factor he took into account was how foreign-sounding a name was. Even though it was just one factor in Richmans analysis, the ACLU recognized it was a chance to show his analysis was unscientific. Ho asked Richman if he would consider the name Carlos Murguia to be a foreign sounding one . When Richman said he would, Ho informed him that Murguia was a federal judge who sat in the courthouse where the trial was being conducted.

Ho launched a similar attack on the credibility of Hans von Spakovsky , a former Justice Department official and member of Trumps now-defunct Presidential Advisory Commission on Election Integrity. Von Spakovsky, another one of Kobachs witnesses testified that he believed voter fraud to be a problem both in Kansas and nationally. But pressed by Ho, von Spakovsky admitted that his understanding of voter fraud in Kansas was based entirely on a list of around 30 voters that Kobachs office had provided to him and that he was not familiar with any of the particular circumstances. He was also forced to admit that some of the research on noncitizen voting he had prepared in the case contained incomplete information that could make it look like there were more noncitizens trying to register to vote than there actually were. Most significantly, von Spakovsky conceded he could not name of a single election in which the outcome was swayed by noncitizens.

Von Spakovsky and Richmans concessions on the stand have called their expertise into question and could now be cited by critics to qualify any of their future claims about noncitizen voting.

Beyond attacking the credibility of voter fraud experts, the ACLU also sought to show how incidents that look like fraud can often turn out to be mistakes. A key piece of Kobachs evidence of voter fraud was a spreadsheet his office had filed of 38 incidences of noncitizens from 1999 until 2017 in Sedgwick County, Kansas. The ACLU highlighted that in several of those examples, people had checked they wanted to register to vote but not that they were citizens (though they did sign an affirmation indicating they were a citizen). After some people got a notification in the mail that they needed to prove they were citizens, they contacted their election office to cancel their registrations. The ACLU used the stories to break down how incidents that seem like nefarious voter fraud can just be mistakes.

Now its up to U.S. District Judge Julie Robinson, a George W. Bush appointee, to ultimately decide whether Kobach gave her enough evidence that noncitizen voter registration in Kansas is a substantial problem. But regardless of what Robinson ultimately rules, the ACLU was able to dive under Kobachs iceberg and show there wasnt much underneath.

During his closing argument in the case, Ho made this clear.

The iceberg, on close inspection your honor, is more of an ice cube, he said.