How to Measure the Partisanship of Every House Seat

What are the most evenly-divided House districts in the country? It’s not as easy as just looking at the past presidential results, considering down ballot races can have their own unique circumstances. That’s why Inside Elections created a metric to measure partisanship in each district.

Inside Elections’ Baseline captures a congressional district’s political performance by combining all federal and state election results over the past four election cycles into a single score. This index aims to approximate what the “typical” Democrat or Republican might receive in any given district.

See Baseline for every state and district in the country in table form here, and in interactive map form here.

What makes Baseline different from some of the other metrics out there is its depth. Most references to competitiveness focus on the margin in the most recent congressional election or the most recent presidential result in the district. It’s also common for other major statewide results, such as Senate and governor, to be broken down by district, especially when those races are competitive.

But Baseline — by design — requires more. Along with the offices listed above, Baseline includes all statewide elections for executive and constitutional offices, from the common (lieutenant governor, attorney general, secretary of state, treasurer, auditor) to the obscure (including mine inspector in Arizona and railroad commissioner in Texas).

Unfortunately, most states don’t…

Methodology: Inside Elections’ Baseline by Congressional District

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California 31: San Gabriel Showdown

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Texas 12 & 26: Pair of Bright Red Open Seats

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Report Shorts (Dec. 1, 2023)

by Erin Covey December 1, 2023 · 2:26 PM EST

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