Partisan gerrymandering can be unconstitutional—at least in theory. In the 1986 case of Davis v. Bandemer, the Supreme Court did not find reason to declare an unconstitutional gerrymander, but its ruling did state “that political gerrymandering cases are properly justiciable under the Equal Protection Clause.”
Despite that ruling, and despite regular rulings against racial gerrymanders over the past five decades, the Court hasn’t actually declared a single political district unconstitutional on the grounds that it disenfranchises voters by political party. In the 2004 Vieth v. Jubelirer case, Justice Antonin Scalia’s ruling on Pennsylvania congressional districts “concluded that political gerrymandering claims are nonjusticiable because no judicially discernible and manageable standards for adjudicating such claims exist.”
That ruling will be tested over the coming weeks, as the Court agreed Monday to review Gill v. Whitford, after a federal district court in November struck down Republican-drawn state assembly maps in Wisconsin on the grounds of partisan gerrymandering. In a story similar to other gerrymandering cases percolating in federal courts now, after grabbing control of the Wisconsin state legislature in 2010, Republicans used the Census-based decennial redistricting as an opportunity to dilute Democratic votes and solidify partisan advantage in the future. That advantage was so effective that at the time of the lower court’s ruling, scholars claimed Democrats would have to win 54 percent of the available votes to regain political control of the state.