A case before the Wisconsin Supreme Court could upend state district voting maps. The new balance on the high court suggests the liberal majority could find the maps unconstitutional.

“What we have here today is a constitutional violation,” said Mark Gaber, an attorney representing Democratic voters who have sued to redraw the state’s legislative district maps.

When the Wisconsin Supreme Court heard oral arguments challenging the state’s legislative district maps, it felt a little like Groundhog Day.

“The districts aren’t contiguous and they violate the separation of powers,” Gaber argued.

Plaintiffs say the case before the high court makes different challenges not addressed by justices in 2022, the last time it ruled on the state’s legislative district maps.

The new arguments primarily centered around the contiguity of some districts, says Marquette Law School research fellow John Johnson.

“They have weird little island areas that are disconnected from the rest of them,” he explained.

These islands were caused by towns being annexed from municipalities over time. One party argued the result violates state constitutional requirements because these districts are not physically contiguous. The other side says contiguity has a broader definition, and the lines as drawn have 50 years of precedent behind them. If the court were to find the maps unconstitutional, an alternative would be needed.

“I think if they choose the separation of powers complaint, then they have to institute entirely new maps,” Johnson said.

“If they only threw out the maps on the basis of the contiguity challenge, then perhaps they would try to come up with a new map that only solved that problem, because the contiguity issue does not affect every district. It affects about half the districts in the state,” he added.

Experts cautioned the justices not to redraw the maps themselves, calling it a slippery slope.

“If we are to find these maps unconstitutional, and we were to turn to someone to help draw the maps, do you have names of people that you would suggest?” asked Justice Rebecca Dallet, a liberal.

Justice Brian Hagedorn, a conservative, pushed both parties on what true partisan fairness looks like for Wisconsin.

“What would be neutral? What’s the acceptable range of Republican- or Democratic-leaning Assembly districts or Senate districts that’s within the permissible range? he asked.

“The key question is which maps are most likely to support rather than force majority rule,” replied Sam Hirsch, another lawyer for the plaintiffs.

Current maps have Assembly Democrats holding 35 seats. Republicans have 64. There are many methods to draw maps, and Johnson said it is possible to calculate a range of partisan fairness.

“Mathematicians have really pioneered over the last few years using algorithms to generate enormous ensembles,” he explained. “You do that in Wisconsin and you get, oh, in the neighborhood of 55, 56, maybe 57 seats leaning Republican in a 50-50 year.”

Johnson described how computers can use partisan voting patterns to perfect maps with specific goals in mind.

“It’s consequential because our technology allows us to more precisely target certain kinds of voters,” he said. “In a fundamental way, gerrymandering works because voters are so polarized between the parties. And I think that that means that really any solution is going to leave a lot of people deeply disappointed.”

No matter how the court rules, there’s no guarantee this won’t happen all over again.

“Is there any end to this litigation?” asked Chief Justice Annette Ziegler, a conservative.

“We’re making it up as we go along,” Johnson said. “If the balance of power on the Supreme Court changed, you could be right back here again.”

If the maps are found unconstitutional, new ones would be needed prior to the 2024 elections.