PIERRE, S.D. — After years of trying to get South Dakota legislators to surrender control of redistricting to an independent commission, supporters of the idea are trying to do it instead through a constitutional amendment.

Backers say the measure before voters this November would eliminate lawmakers’ conflict of interest and make people feel elections are fair to all parties.

“It’s time for fair representation. Period,” said Democratic Rep. Peggy Gibson, who has backed at least nine independent redistricting measures since 2009. “I’m not saying it’ll be perfect, but I’m certainly thinking it will be better than the method that we have now.”

Opponents — including majority Republicans — say the current system is working fine.

“The idea, I think, is to elect people that are more in line with liberal ideas as far as spending money and a whole host of issues,” said GOP Rep. Jim Bolin, who served on the commission that oversaw the last redistricting plan in 2011.

Members of the South Dakota Farmers Union decided to gather signatures for a constitutional amendment after their last failure at the Legislature. The group has given at least $238,000 in cash and in-kind contributions to a political committee supporting the effort, according to state campaign finance reports.

Redistricting is the process of redrawing electoral district boundaries every 10 years to account for population changes. When the process is carried out by elected officials, it often sparks lawsuits and claims of gerrymandering — attempting to draw the districts for political advantage.

Passage of South Dakota’s Amendment T requires a simple majority. It would create a commission of nine people chosen each redistricting year to revise the legislative district boundaries.

No more than three commission members could be part of the same political party, and none could be elected officials in the legislative or executive branches, among other prohibitions. The plan also says party registration and voting history must be excluded from the redistricting process, and that the residency of incumbents or candidates can’t be identified or considered.

Opponents argue the plan is meant to tip the political balance toward Democrats. Republicans now hold every statewide office and supermajorities in both legislative chambers, and registered Republicans far outnumber registered Democrats.

The 2011 plan passed with a vote mostly along party lines, with minority Democrats complaining it put them at a disadvantage. Bolin insisted it was fair. He called the amendment “part of a crazy plan to change things around.”

Jon Schaff, a political science professor at Northern State University, said the current process probably does favor the Republican majority.

“I don’t think anybody thinks that even with neutrally drawn districts that Democrats would control the House or the Senate, but it’s likely that the numbers of Democrats would go up,” he said.

Political considerations get no mention in redistricting guidance provided by the state constitution. It just says each legislative district must consist of “compact, contiguous territory and shall have population as nearly equal as is practicable.”

Reuben Bezpaletz, a former Legislative Research Council staff member who worked on redistricting plans from 1981 through the 2011 redistricting, wouldn’t take a position on the measure. But he said it’s critical that districts are drawn when possible so that either party could win.

“I believe the creation of competitive legislative districts is the most important single thing that you can do to preserve democracy by giving voters a real choice,” he said.