Proposed Redistricting Standards Now Include Three Tests
Two Additional Methods Added Following Input
S.B. 1011 Redistricting Standards would establish three clear tests in state statute to assess whether congressional maps treat political parties fairly.
This legislation is in response to a recent ruling by 3rd District Court Judge Diana Gibson, who found that the language of Proposition 4 was too “general” and “non-specific.” In her decision, Judge Gibson invited lawmakers to define clear criteria using “the best available data and scientific and statistical methods to use in evaluating redistricting plans for compliance with … Proposition 4.”
“We sought feedback, and I appreciate my colleagues, including members of both parties, and members of the public for their input,” said Sen. Brady Brammer, sponsor of the bill. “In response, we added two additional tests to ensure the analysis of maps is more robust to identify undue favoring or disfavoring of any party—whether that party be Republicans or Democrats.”
This bill implements three statistical methods, as invited by Judge Gibson’s ruling, including the partisan bias test and the mean-median difference test, that:
- Establishes a clear, objective and data-driven pass/fail test to determine whether a map meets the test of partisan symmetry.
- Minimize ambiguous language, giving Utahns and courts clear and workable standards.
- Reduces the likelihood of prolonged litigation.
- Enhances transparency, consistency and accountability in the redistricting process.
“This isn’t about favoring one party over another; it’s about ensuring the rules are fair and consistently applied,” said Sen. Brammer. “Clear standards increase accountability, reduce years of costly legal battles and help restore public confidence in the redistricting process. Evaluations of compliance with Proposition 4 should be objective and not merely a Rorschach test.”
The Redistricting Standards align the state with established national legal precedent by codifying a statistical, data-driven approach to assess whether congressional maps treat political parties fairly.
Key Provisions of the S.B. 1011 Redistricting Standards:
The Three Statistical Methods
- Partisan Bias Test
- Pass/fail: 0 for the current map with four seats. +/-1 and +/-2 fail.
- The test played a key role in the U.S. Supreme Court landmark decision Gill v. Whitford (2017). Similar analyses have been used to invalidate manipulated maps in states such as Pennsylvania and North Carolina.
- Ensemble Analysis
- Pass/fail: Must be within the acceptable bounds of 2.5% and 97.5% with no outliers.
- Detects purposeful favoring or disfavoring of any party.
- Democrat-proposed test.
- Mean-Median Difference Test
- Pass/fail: No deviation above 2% between the mean and the median.
- Provides another method, in addition to the partisan bias test, to measure undue favoring or disfavoring of any party.
- Democrat-proposed test.
The Legislature will consider the bill during the special session on Monday, October 6, 2025.
Tags: S.B. 1011 Redistricting Standards, Sen. Brady Brammer