Utah’s redistricting lawsuit is back in court for a two-day hearing. With more legal complications in the mix in recent weeks, the focus is more immediate: What congressional boundaries will Utah use in 2026?
In the highly technical first day hearing, Oct. 23, with discussion of redistricting algorithms and academic literature, plaintiffs put their experts on the stand before Third District Court Judge Dianna Gibson. Attorneys for the plaintiffs and defendants spent significant time in their questioning trying to point out flaws in the other side’s map, as well as their respective witnesses and methodologies. Both sides brought boxes full of evidence, a stack of papers growing ever higher on Gibson’s desk as the hearing went on.
The clock is ticking. The Lt. Governor’s Office said a map needs to be in place by Nov. 10 to be used in the 2026 election.
The Legislature is trying to convince the judge that the boundaries backed by Republican state lawmakers, called Map C, comply with the 2018 citizen-approved ballot initiative Proposition 4, which codified redistricting standards, including a ban on gerrymandering.
Attorneys for plaintiffs — including the League of Women Voters of Utah, Mormon Women for Ethical Government and a handful of Utah voters — argue that the Legislature’s preferred map does not meet those standards and unlawfully favors Republicans. Plaintiffs have submitted two maps of their own in this case.
The plaintiff’s expert witnesses accused the Legislature’s map of unduly favoring Republicans. Attorneys spent hours questioning the five witnesses, including three professors from across the country who spoke as experts and two Millcreek residents who spoke as individual voters.
University of Michigan political science professor Jowei Chen studies redistricting and has testified in similar cases across the country. He repeatedly called the Legislature’s preferred map an “extreme partisan outlier” that favored Republicans and “cracked” areas with Democratic voters.
Chen programmed an algorithm to make 10,000 computer-simulated Utah congressional maps that he said complied with the neutral standards of Prop 4. He then compared the partisan distribution of his 10,000 maps on a district-by-district level to the Legislature’s Map C. In over 99% of the simulated maps, one of the four districts favored Democrats. Map C, he said, favors Republicans in all four districts.
Chen didn’t mince words
“It is an extreme partisan outlier. It is more heavily Republican than almost all of the computer-simulated” districts he compared it to, Chen said while walking through his report. Throughout hours of questioning, he reiterated how Map C was unusual in how far it fell outside the normal range of distribution in his simulation.
Map C was drawn by the Legislature’s hired expert Sean Trende, who has a Ph.D. in political science and works as a senior elections analyst for conservative news site RealClearPolitics.
Trende also created a series of 100,000 computer simulations to compare with his map. Chen criticized that set, alleging they did not follow the Prop 4 standards.
In Chen’s report, he said that the maps that more severely violated Prop 4 standards tended to create a more Republican-favoring map.
Chen also took issue with the fairness test Trende used on his simulated maps. Both Chen and one of the plaintiff’s other experts said the partisan bias test is not appropriate in Utah, where one party dominates statewide elections, since the test is based on a 50-50 split between parties. By using that, Chen said Trende weeded out maps that were more favorable to Democrats.
Utah lawmakers recently codified the partisan bias test, along with two others, to adjudicate congressional maps. The plaintiffs are also challenging that.
Those three tests were the focus of the plaintiff’s other expert witness, Georgetown University public policy professor Christopher Warshaw, an expert on redistricting and American politics. Specifically, he believed the partisan bias test and mean-median difference test were not appropriate in Utah.
“It is not among the best available measures, and in fact, it's among the worst measures [for Utah],” Warshaw said.
He said the tests produce strange results and pointed out that two recent academic papers stated that using the partisan bias test is particularly a bad idea in Utah, calling it the “Utah Paradox.” When the test is used in Utah, academics found that it labels a map with four Republican-friendly districts as a fair map, whereas a map with one Democrat-leaning district is labeled a pro-Republican gerrymander.
The tests are important in the debate over what boundaries to use next year because the law now says those are the only tests that can be used to judge whether maps are fair, including in Judge Gibson’s review.
University of Delaware political science professor Kassra Oskooii was hired by plaintiffs to adjust their first map to improve contiguity, or borders. He was also asked to adjust the Legislature’s Map C to reduce municipal splits. The result was plaintiffs’ Map 2.
Cross-examination of the plaintiff’s other witnesses by the Legislature’s attorneys was relatively brief. But with Oskooii, attorney Tyler Green had a more critical line of questioning. Green displayed various maps on the screen and zoomed in on specific boundaries, suggesting certain communities were inappropriately placed together or moved around.
The plaintiffs also called those personally impacted by this case to the stand. Millcreek resident Victoria Reid, a registered Republican as well as a member of Mormon Women for Ethical Government, testified she thinks Map C is somewhat better than the state’s 2021 congressional map, which split Millcreek up four ways, but she thinks it is still problematic. Map C splits Millcreek into two districts. Reid said she can walk to each from her home.
“I don't really feel like the map respects our community,” Reid said.
Millcreek, she said, has worked hard to create a sense of place for its residents.
“I feel like this map really undercuts that effort,” Reid said.
Day two of the hearing will see the defendant’s three expert witnesses on the stand.
After that, both will submit more written arguments to the court. Gibson will have to decide whether Map C followed the law and can be used, or if another map should be the pick.
