As recently as 2015, the Court made clear that partisan gerrymanders are "incompatible with democratic principles". Voting 5-4 along ideological lines in a separate order, the justices said state officials don't have to comply with a lower court order to put a new redistricting map into effect by November 1. Similar cases are pending in North Carolina and Maryland.
Republicans argue they are successful because they run better candidates in a state that is trending Republican.
Rather than issue a ruling, however, the high court said it will hear the case on the merits. If the Supreme Court rules that partisan gerrymandering such as this is unconstitutional, then our democracy will be protected from such cases of minority rule.
A dozen Wisconsin Democratic Party voters in 2015 sued state election officials, saying the redistricting divided Democratic voters in some areas and packed them in others to dilute their electoral clout and benefit Republican candidates.
The district court panel agreed, invalidating the restricting plan statewide.
Although the court did not explain its willingness to schedule a hearing at the same time that it voted to block the lower court ruling in the meantime, its actions on Monday were not favorable to the challengers of the Wisconsin plan.
A three-judge court struck down the districts as an illegal partisan gerrymander and ordered new ones to be put in place for the 2018 elections. And the reverse applies in Democrat states, although they are fewer in number. In Virginia, where President Trump lost handily, Republicans have 66 of 100 seats in the House of Delegates.
The ruling stated there was no question that "the map was created to make it more hard for Democrats, compared to Republicans, to translate their votes into seats".
As a result, congressional lines have become ever more partisan in recent years.
Critics have argued the current legislative maps unfairly stack the deck for Republicans district by district, pointing to the 2016 presidential election results as an example. Democrats won 56% of the vote but 71% of the seats where they controlled the process.
The judges said the redrawing violated constitutional guarantees of equal protection under the law and free speech by undercutting the ability of Democratic voters to turn their votes into seats in the Wisconsin state legislature.
"Austin and most of Travis County easily could be its own congressional district", Li said.
Redistricting experts widely believed justices would hear Wisconsin's appeal because it's so unusual.
The Supreme Court announced Monday morning it will take up the most important gerrymandering case in more than a decade. The four liberals (Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor, and Elena Kagan) dissented.
A ruling that partisan gerrymanders are unlawful would dramatically recast the apportionment process and shuffle the balance of power in Congress and state legislatures.
Smith and Potter's group noted that legislative aides created Wisconsin's partisan gerrymander six years ago with hired consultants in a secret room in a private law office. And the justices must also decide whether they even have the jurisdiction to rule in the Wisconsin case, a question they left open in accepting the case.
"The threat of partisan gerrymandering isn't a Democratic or Republican issue; it's an issue for all American voters", Potter told The Washington Post.
SCOTUS has struck down racial gerrymandering but not partisan gerrymandering. Their test, known as the "efficiency gap", focuses on how frequently votes in a particular district are effectively wasted, either because they go to a candidate who loses or because they provide the victor with more support than was necessary.