The court ruled 4-3 in favor of the Democrats, who argued that the current maps are unconstitutional due to non-contiguous districts and a violation of the separation of powers doctrine.

The lawsuit was filed shortly after the court's majority shifted to liberal control last August when Justice Janet Protasiewicz joined the bench following her election victory in April. Protasiewicz, who had campaigned against the GOP-drawn maps, referred to them as "unfair" and "rigged" before siding with the other liberal justices in striking them down.

The ruling holds significant implications as Wisconsin is considered a battleground state, with close margins in previous presidential elections. Additionally, Republicans have held large majorities in the Legislature under the decade-old maps they drew.

Republican Assembly Speaker Robin Vos, who had previously threatened to impeach Justice Protasiewicz, has now backtracked and expressed that impeachment is highly unlikely, even if she ruled against the maps. The ruling also arrives just a month after oral arguments were heard in November, and the state elections commission has stated that new maps must be established by March 15 to be implemented in time for the 2024 election.

Democrats have advocated for all 132 lawmakers to undergo elections under the new maps, including half of the state Senate members currently serving their four-year terms. On the contrary, the Legislature argued against enacting any new maps earlier than the 2026 election.

According to Democrats, the majority of current legislative districts in Wisconsin fail to meet the state constitution's contiguity requirement. Attorneys for the Legislature countered this argument, referencing previous state and federal court rulings that have allowed non-contiguous districts under certain conditions. Republicans noted that any addressable issues should pertain only to non-contiguous districts and should not disrupt existing district lines.

The Republican-controlled Legislature solidified their majorities with the electoral maps drawn in 2011, currently standing at 64-35 in the Assembly and a 22-11 supermajority in the Senate. Since gaining the majority, Republicans have pursued an array of conservative policies, such as reducing collective bargaining for public workers. They have also impeded Democratic Governor Tony Evers' agenda by terminating his appointees and even threatening impeachment of Justice Protasiewicz and the state's elections leader.

The ruling of the Wisconsin Supreme Court adds to the ongoing litigation occurring in numerous states concerning U.S. House and state legislative districts enacted after the 2020 census. The outcome of these cases will likely have far-reaching consequences for the future political landscape in many states across the country.