But a new analysis of election results by The Associated Press indicates it was Republicans who could have benefited slightly from the way the districts were drawn, contributing to what would become a landslide election for the GOP. It's created to detect cases in which one party may have won, widened or retained its grip on power through political gerrymandering.
The analysis showed that Idaho is among the top 10 states in the country with the biggest "efficiency gap", or the percentage of seats won by Republicans beyond what would be expected based on their statewide average share of votes. The majority and minority party leaders in each legislative chamber each select one person to serve on the commission; the state chairmen of the Republican and Democratic parties also each select a commissioner. Their mathematical model was cited last fall as "corroborative evidence" by a federal appeals court panel that struck down Wisconsin's Assembly districts as an intentional partisan gerrymander in violation of Democratic voters' rights to representation.
Likewise, he said state Senate maps are drawn fairly, but Democrats underperform in districts they should win. Idaho has only two districts, both of which were won by Republicans in November.
Roughly 20 percent of seats up for election had just one major party candidate - seven for Republicans and six for Democrats.
Ultimately, Republicans picked up a 13th district in a state where registered Democratic voters outnumber Republicans by a margin of 4 to 3.
The investigation used a new statistical method of calculating partisan advantage, developed by University of Chicago law professor Nick Stephanopoulos and Eric McGhee, a researcher at the nonpartisan Public Policy Institute of California, called the "efficiency gap".
The efficiency gap is the subject of a lawsuit before the U.S. Supreme Court. It cuts through three counties - and has three House seats, two held by Democrats. And they moved Republican-performing areas into closely divided districts held by Republican incumbents.
That means that Louisiana's one Democrat, Rep. Cedric Richmond of New Orleans, to five Republicans in the House is a healthy outcome for the state.
The analysis found Republicans won 56 percent of the votes in Ohio House races yet 66 percent of the seats. But in the end, Maine's districts remained much the same as they had been even as gerrymandering produced odd-shaped districts in other states.
In Pennsylvania, Republicans won 13 of the 18 congressional seats previous year, three more than would be expected based on the party's vote share, according to the AP analysis.
For Democrats to complain of gerrymandering is "pure nonsense", said Matt Walter, the Republican committee's president.
In Texas, Republicans gained almost four excess congressional seats compared to projections from a typical votes-to-seats ratio, according to the AP's analysis.
