Arizona's independent commission produced districts that matched the state — but will it last?

Daily Kos Elections is out with new data from Arizona breaking down the 2020 presidential results for each district in the state legislature. Republicans maintained the narrowest possible majorities in both chambers last year even as Joe Biden became the first Democrat to take the state's electoral votes in the 21st century.

The Grand Canyon State is divided into 30 legislative districts, with each electing one senator and two state representatives every two years; the districts are exactly the same (or "perfectly coterminous") for both chambers. Last year, Biden and Donald Trump each carried exactly half of the districts as Biden was prevailing statewide 49.4-49.1, but crossover voting was just enough to keep Republicans in power. As you'd expect when both candidates each carried half the districts, the two median districts when averaged together come close to reflecting the statewide result itself, with Biden winning them 50-48 for a Democratic median seat advantage of just one point.

Despite a strong Democratic campaign to flip the legislature, they netted just one seat in the Senate, knocking the GOP's majority from 17-13 to 16-14, while Republicans maintained their 31-29 edge in the House.

We'll start in the Senate, where just one lawmaker holds a seat carried by the other party's presidential candidate. That incumbent is Republican J.D. Mesnard, who prevailed 53-47 in LD-17, which includes a large part of Chandler in the Phoenix area, even as Biden won his constituency 51-47.

The only other Senate Republican who won a closer race was Paul Boyer, whose LD-20 around Glendale backed Trump just 49.2-48.9. Boyer, though, still ran several points ahead of the ticket to win 52-48. Split-ticket voting wasn't quite enough, however, to save Republican state Sen. Kate Brophy McGee, who lost to Democrat Christine Marsh 50.2-49.8 as Biden was carrying the Phoenix-based LD-28 by a 55-43 margin.

In the House, the electoral rules are a bit different. Each party can nominate up to two candidates for each district, and voters can vote for their top two choices in the general election, with the top two vote-getters winning. Sometimes, though, parties will choose to nominate only one candidate in a tough constituency and encourage their voters to not select a second contender, a tactic known as "bullet voting." The hope is that, by ceding one seat, the party will increase its chances to take the other one, and as we'll see, this maneuver did indeed seem to aid both parties last year.

Two House Republicans represent Biden districts, but unlike in the Senate, there's one Democrat in a Trump seat. That Democrat is Judy Schwiebert in the aforementioned LD-20, who was her party's only nominee here: Schwiebert took first place with 34.4%, while Rep. Shawnna Bolick edged out fellow Republican incumbent Anthony Kern 33.5-32.0.

Bullet voting, though, also likely secured the GOP control of a seat in LD-04, a geographically vast constituency in the southwestern corner of the state that backed Biden 56-43. Democratic state Rep. Charlene Fernandez led with 40%, but Republican Joel John beat out the district's other Democratic incumbent, Geraldine Peten, 32-29 for second.

The other Republican-held Biden seat in the House is also in LD-17, where one incumbent from each party ended up winning. Democratic state Rep. Jennifer Pawlik, who was Team Blue's sole nominee, led with 33.8%, while Rep. Jeff Weninger defeated fellow Republican Liz Harris 33.4-32.8.

Democrats may have another chance to flip either chamber of the legislature in 2022 if the new map looks similar to the current one, but redistricting will be an especially unpredictable affair in Arizona.

The state's congressional and legislative maps are drawn by an ostensibly independent commission, but Republicans have done everything they can to hijack it: Its nominally independent tiebreaking member has troubling ties to the GOP and has repeatedly sided with Republican commissioners on a variety of preliminary matters, such as hiring a map-drawing consultant who testified as an expert witness in support of a Republican gerrymander in North Carolina that was struck down by the courts.

P.S. You can find all of our district-level data at this bookmarkable permalink.