The Legislature’s main expert witness said Friday that a new congressional map adopted by Republican lawmakers favors the GOP, but that doesn’t mean Utah Democrats couldn’t win a U.S. House seat or two.
“If they run [former Congress member] Ben McAdams in one and [independent] Evan McMullin in the other,” said Sean Trende, an elections analyst for the political website RealClearPolitics, “they’re going to have half the delegation.
“There are two districts in this map,” he added, “that are more Democratic than the district that elected two Democrats and had very close races [under the 2011 map].”
Democrat Jim Matheson won Utah’s 4th District in 2012, and McAdams won the same seat in 2018 before narrowly losing it in 2020. The district at the time was more heavily Republican than the most Democratic district in the map now proposed by the Legislature.
Trende’s testimony came on the second day of courtroom hearings before 3rd District Judge Dianna Gibson, who must decide which of three maps — one from the Legislature and two from the plaintiffs in the case — best complies with the redistricting standards in the 2018 voter-backed Better Boundaries initiative and should be used in Utah’s 2026 U.S. House election.
The Legislature essentially repealed the initiative in 2021, but last year the Utah Supreme Court ruled that action was unconstitutional, because it deprived Utah voters of their right to make law through the initiative process.
Gibson did not rule Friday. She has to decide which map will be used by Nov. 10, so county clerks can make preparations for the 2026 midterm elections.
(Francisco Kjolseth | The Salt Lake Tribune) Michael Barber, a political science professor at Brigham Young University, is called for expert testimony for the state during Utah’s latest congressional maps process on day two of testimony, before Judge Dianna Gibson in Salt Lake City.
Asked about how she felt the two days of testimony went, Katharine Biele, president of the Utah chapter of the League of Women Voters, which is one of the plaintiffs, said that “it’s very difficult to say.”
“There was a lot of technical testimony. Most of it went right over our heads,” she said. “I think [Gibson] has a lot of work ahead of her.”
Ultimately, Trende and and another witness for the Legislature, Brigham Young University political science professor Michael Barber, testified that the map the Legislature has submitted to the court passed whatever test was applied to it — while two maps that the plaintiffs submitted for consideration did not.
“My bottom-line conclusions are that the 2025 [legislative] map is pretty unremarkable,” Barber said. “It doesn’t stand at the edge of any of these tests. … [With the plaintiffs’ maps] it’s certainly much less the case. They fall at the edges more often.”
A day earlier, experts for the the plaintiffs — the League of Women Voters, Mormon Women for Ethical Government and a handful of voters impacted by the current map — panned the Legislature’s map, calling it a partisan “outlier” that creates four safe Republican districts.
The plaintiffs’ experts criticized the tests the Legislature identified that can be used to determine if a map is biased. These experts contend the computer-generated maps used for comparison against the Legislature’s map didn’t follow standard redistricting criteria and the other tests would weed out nearly all of the competitive or Democrat-leaning maps.
About half the maps Barber’s algorithm originally generated, for example, produced a competitive or Democrat-leaning district. After the Legislature’s bias tests were applied, the number fell to about 6%.
Trende described how he drew the map that the Legislature ultimately adopted — something he said he was reluctant to do.
“I didn’t want to be the map drawer,” he said. “I didn’t want to be sitting here.”
(Francisco Kjolseth | The Salt Lake Tribune) Sean Trende, an election analyst for RealClearPolitics, provides testimony during a hearing on congressional redistricting maps before Judge Dianna Gibson in 3rd District Court in Salt Lake City on Friday, Oct. 24, 2025.
Trende said he started with the map the Legislature passed in 2021 and used in the past two elections — and then refined it, starting with removing a four-way split of Salt Lake County.
“That’s the first thing that jumps off the page,” he said. “I don’t like this.”
After making a handful of other alterations, Trende said, he compared the Legislature-adopted map against two sets of 100,000 computer-generated maps and determined the legislative map fell within the acceptable range for partisan bias.
“No matter what I looked at,” Trende said, “the map passed” that test.
On cross-examination, Trende acknowledged that he drew the map on a program — Dave’s Redistricting — that included partisan data while he was creating the boundaries. Proposition 4 bars the Legislature from using partisan data when crafting maps, and lawmakers were adamant that no partisan information was used.
Trende said he was not told to create the maps without using partisan data and dismissed the information displayed as a “worthless composite” of election results going back to 2012 that wouldn’t have revealed anything useful.
(Francisco Kjolseth | The Salt Lake Tribune) Plaintiffs' attorney Mark Gaber cross-examines testimony by Sean Trende during a hearing on congressional redistricting maps before Judge Dianna Gibson in 3rd District Court in Salt Lake City on Friday, Oct. 24, 2025.
The plaintiffs’ attorney, Mark Gaber, grilled Trende on a series of cases in which his expert testimony had been largely dismissed by courts — a voting rights case in Georgia, a redistricting case in Maryland and another in Louisiana, where the judge called his analysis “fundamentally flawed and completely useless.”
Trende said, based on the information he was asked to provide and the legal conclusions of the court, he agreed his testimony was useless in those cases.
Barber was an expert witness in a Florida case in which the judge said his testimony was “emphatically not credible.”
Barber’s testimony took aim at computer-generated maps created by the plaintiffs’ expert, Jowei Chen, a University of Michigan political science professor, which the BYU scholar said showed an alarming tendency to produce maps with a northern Salt Lake County — and heavily Democratic — district and three overwhelmingly GOP districts.
Gaber countered by going through numerous maps Barber’s algorithm generated that had irregular shapes, straddled the Great Salt Lake or snaked around most of the state. Barber acknowledged that his coding treated Salt Lake County differently than Utah’s other 28 counties, because the county has more than the 817,904 target population for a congressional district.
That meant that roughly 60% of the maps Barber generated split Salt Lake County four ways.
(Francisco Kjolseth | The Salt Lake Tribune) Third District Judge Dianna Gibson listens to a hearing on congressional redistricting maps in Salt Lake City on Friday, Oct. 24, 2025.