Third District Judge Dianna Gibson is hearing testimony for a second day Friday as experts hired by the Legislature will make the case that the map adopted by Republicans is fair and doesn’t disadvantage Democrats:.
2:30 update
Witness: Dems could win one to two seats
The Legislature’s main expert witness, Sean Trende, said Friday that tests that show congressional districts might favor Republicans doesn’t mean that Democrats can’t win a U.S. House seat.
Asked by the attorney for the Legislature, Tyler Green, if he thought Democrats could win a seat in the districts the lawmakers chose, Trende, an election analyst for RealClearPolitics, said his first thought was that Democrats might “make hay” from the partisan characteristics of the map.
“The second reaction is: If they run [former Congress member] Ben McAdams in one and [independent] Evan McMullin in the other,” he said, “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].”
(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.
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.
On cross-examination, Mark Gaber, the plaintiffs’ attorney, pointed to several cases where Trende’s testimony had been largely dismissed by the court — including a Louisiana case where the judge called it “fundamentally flawed” and “completely useless.”
The Legislature will have one more witness to testify, Brigham Young University political science professor Michael Barber, before the hearing adjourns.
(Francisco Kjolseth | The Salt Lake Tribune) Michael Barber, a political science professor at Brigham Young University, testifies during a hearing on congressional redistricting maps before Judge Dianna Gibson in 3rd District Court in Salt Lake City, on Thursday, Oct. 23, 2025.
11:30 update
Legislature’s expert: No partisan advantage
An expert who drew the map adopted by the Legislature told the judge Friday that he did not use partisan data when he was producing the map and, when he did apply election results, the map did not unduly favor either political party.
The testimony from Sean Trende, hired as a consultant and expert by the Legislature, stood in stark contrast with the assessment offered Thursday by witnesses for the plaintiffs, who called Trende’s map an “outlier” that creates four Republican seats.
Trende said that when he drew the map enacted by the Legislature, he started with the current boundaries and tried to fix some problems — the first among them, the four-way split of Salt Lake County.
“That’s the first thing that jumps off the page,” he said, “I don’t like this.”
He applied an east-west split of the county and then made other revisions to avoid carving Salt Lake City in half.
After making a handful of other revisions, 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.”
9:52 a.m. update
Legislature defends its map
Lawyers hired by the Legislature first put on Jonathan Katz, a social sciences and statistics professor at the California Institute of Technology, to discuss the “partisan symmetry” test — one of the tests the GOP-dominated Legislature has said can be used to determine if the lawmakers’ map is fair.
On Thursday, the plaintiffs challenging the Legislature’s map — the League of Women Voters, Mormon Women for Ethical Government and a handful of voters impacted by the current map — presented testimony that the Legislature’s map is an “outlier” that creates four safe Republican districts and deprives Democrats of a competitive seat.
(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.
In August, Gibson scrapped the existing map adopted by the Legislature in 2021, ruling that it failed to comply with Proposition 4, the Better Boundaries initiative approved by voters in 2018 with the goal of banning partisan gerrymandering.
The Legislature largely repealed that initiative, but the Utah Supreme Court ruled last year that the repeal unconstitutionally deprived Utah voters of their right to change laws through the initiative process.
Gibson has until Nov. 10 to choose a map to be used in the 2026 midterm elections. The Legislature has submitted one map, while the plaintiffs in the case have produced two potential options.