And the system may get held up in court, because civil rights groups are bound to contest the voter-approved mandate that legislative lines be based only on the population of adult citizens — not all people, as is the case almost everywhere.
Voters in both Colorado and Michigan approved truly independent commissions in 2018. Once the population details from this year's census are finalized, next year they will set about realigning their state's congressional and legislative boundaries alongside similar panels in five other states: Arizona, California, Idaho, Washington and Montana, the last of which is likely to get a second House seat thanks to population growth.
But another such commission, approved by the voters in Utah in 2018, was essentially neutered this year, when the GOP-majority Legislature enacted a law saying the panel's work was advisory only.
Alaska will also use an independent commission, but only for its legislative maps since it has a single at-large House district. Hawaii and New Jersey will employ commissions made up of politicians, but in general they may not run in the districts they draw.
But the redistricting power will remain in the hands of elected politicians in more than three-quarters of the states. The GOP has secured the dominant advantage for a second straight decade because it has won unfettered control over the process in 21 states — Texas, Florida, Ohio and North Carolina among them — accounting for as many as 185 House seats, better than two out of every five, depending on precisely how reapportionment turns out.
Although it's not clear how many more districts they can carve out for themselves than they did in 2011, their continued redistricting advantage will only help the Republicans' already solid prospects for picking up the half-dozen or so seats they will need to win back the House in 2022. Such midterm elections almost always favor the party not in the White House in any case.
Control of redistricting in each state
Sources: Princeton Gerrymandering Project, National Conference of State Legislatures
Democrats will dictate the mapmaking terms in just nine states likely to be allocated a combined 66 seats, Illinois by far the biggest among them. Pennsylvania and New York are the biggest of the other nine, with about 70 seats, where there will be divided control over the governor's mansions and statehouses.
Democrats were hoping to break some of the GOP strongholds in state capitals, but their blue wave never formed. In fact, the only legislature that flipped this fall was New Hampshire's — in favor of the GOP.