The United States Supreme Court agreed on Monday to hear the state of Wisconsin's appeal of a 2011 lower court decision, which ruled that a Republican-drawn map of the state's districts was partisan and unconstitutional, the Hill reports.
Wisconsin Republicans won nearly two-thirds of seats in the state legislature the year after the map was introduced, despite having received less than half of the vote.
The Supreme Court's decision will likely have an immense effect on the parameters of gerrymandering—or re-drawing congressional districts for the purpose of strengthening one political party at the expense of another—in at least a dozen states, the Brennan Center for Justice said in a statement published Monday.
"Wisconsin's gerrymander was one of the most aggressive of the decade, locking in a large and implausibly stable majority for Republicans in what is otherwise a battleground state," Thomas Wolf, the Brennan Center's redistricting counsel, said in the statement. "It's a symptom of politics going haywire and something that we increasingly see when one party has sole control of the redistricting process."
The court hasn't ruled on "purely partisan gerrymanders" since 2004.