Colorado’s highest court on Monday heard arguments over whether state legislators have the authority to enact a law that would adjust the voter-approved state redistricting process, with several justices skeptical of the legality or prudence of lawmakers’ proposal.

At issue is a bill advanced by lawmakers that aims to keep the state’s redistricting commissioners on track to finish new political maps this fall, even though census data that would normally have been delivered to states in March is delayed until at least August.

The bill, Senate Bill 21-247, would define what “necessary census data” means, so survey and estimate data could be used instead. Their bill also seeks to prescribe the way courts could evaluate the redistricting commission’s adherence to constitutional requirements.

The redistricting commissions have pushed back, saying lawmakers overstepped their boundaries by trying to meddle in a voter-approved system that is codified in the state constitution, and which was passed with the goal of removing lawmakers from the process.

The issue is untested, since the independent redistricting commission process was only approved by voters in 2018. Past redistricting efforts have been done by lawmakers or legislative staff, but several of the state’s district plans over the past few decades have been overturned and redrawn by courts.

“I think about just the optics of this,” said Justice William Hood, “with this being the first time out of gate, and the General Assembly is already monkeying with the way this is going to work, when it’s supposed to be an independent commission.”

Justice Carlos Samour echoed Hood’s criticism: “It gives me some heartburn when we have a couple of amendments that were specifically passed to take this away from the legislature, and then here we are, almost immediately the legislature is trying to get its hand back into the process.”

An attorney representing the legislature said that because amendments Y and Z, the voter-approved measures establishing the independent redistricting commission system, didn’t specifically prohibit the legislature from writing laws like SB 247, the legislature is empowered to do so.

Justice Monica Márquez focused her skepticism on the bill’s goal of having the courts use a lesser “substantial compliance” standard for evaluating the redistricting commissions’ adherence to the constitutional provisions in amendments Y and Z.

“Are you aware of any other circumstance in which the legislature has imposed a substantial compliance standard on the interpretation of a constitutional amendment? That’s the whole origin of that concept anyway,” Márquez asked. “Why isn’t that something that the court, at some point later on down the road, we decide for ourselves?”

The attorney for the legislature answered that requiring the substantial compliance standard for redistricting reviews would be analogous to past decisions to use the standard on voter-approved amendments.

The redistricting commissions took the position the part of the bill requiring the specific judicial standards is another overreach by the legislature.

But more importantly, as one of the commissions’ lawyers said in court, the commissions believe the legislation “is unconstitutional because it’s a solution to problem that doesn’t exist.”

The commissions have moved forward with plans for how to work on maps, even without the decennial census data. They’ve adopted plans similar to what the legislature proposed, but as the commissions’ lawyers stressed repeatedly, they believe it’s their decision to make, and not elected lawmakers.

The state Supreme Court is expected to rule on the matter in the coming days to weeks. If the court approves the legislation, it will go to Gov. Jared Polis for a final signature. In the meantime, the redistricting commissions continue to move forward with their plans, including having preliminary draft maps by the end of June.