A large part of the Republican control of the US House is due to the last redistricting based on the 2010 Census. From Five Thirty Eight:
"Republicans’ astounding state legislative gains in the 2010 midterms — the year before the decennial redistricting cycle — allowed them to redraw four times as many congressional districts as Democrats in 2011 and 2012, stretching their geographical edge even further. As a result, in 2012, Democrats won 51 percent of all major-party votes cast for House candidates but just 47 percent of all seats. In 2014, Democrats won 47 percent of all major-party votes but just 43 percent of the seats. Amazingly, just 16 of 247 House Republicans won their races by fewer than 10 percentage points."There's currently a redistricting challenge that has been accepted by the Supreme Court. From the Wisconsin State Journal:
"The three-judge panel that heard the Whitford case last year weighed the evidence and ordered the maps redrawn. The state has appealed the decision to the U.S. Supreme Court, arguing the process was lawful. The Supreme Court stayed the lower court order and agreed to hear oral arguments as early as this fall."The Court hasn't ruled on political gerrymandering saying it was hard to get an objective sense of it. But the Wisconsin legal team has come up with a way to measure
"the Whitford plaintiffs devised a three-pronged standard for partisan gerrymandering: Proving discriminatory intent, demonstrating a discriminatory effect, and finding no other justification for how the maps were drawn.
To prove the discriminatory effect, the plaintiffs measured the election results based on what is known as the "efficiency gap," which seeks to calculate how many votes for a given party are "wasted" because its voters are "packed" into certain safe districts or "cracked," that is, placed into districts where they still can't muster enough support for their candidate to win.
The Whitford plaintiffs argued the Wisconsin legislative districts were the most gerrymandered in the past 40 years, with 13 percent of votes wasted in 2012 and 10 percent wasted in 2014. Based on an analysis of 786 legislative elections across the country, they argued a gap of more than 7 percent should be deemed unconstitutional."
This will be a huge case either way it is decided. If the Court goes with the plaintiffs, it should slow down partisan gerrymandering. If not, it probably signals the issue is probably dead until there is a significantly new Supreme Court.
I wrote about this case back in February.