Heavy growth in Republican areas could aid GOP in Arizona redistricting

Arizona's population growth over the past decade was largely in Maricopa County and was especially concentrated in predominantly Republican suburban areas, a trend that could favor Republicans as the state prepares to redraw its legislative and congressional districts.

According to the 2020 census, Arizona's population grew by about 760,000 people, an increase of 11.9%. Of those new residents, more than 600,000 were in Maricopa County, while nearly 50,000 were in Pinal County, primarily in Phoenix metro area's suburbs and exurbs.

The most explosive population growth in the state was in the far ends of the East and West Valley, both of which have historically been reliably Republican areas. Phoenix, a Democratic stronghold over the past decade, gained 162,000 residents in the census. Much of that growth was in the northern, predominantly GOP areas of the city.

Democrats, Arizona's minority party for decades, have made noteworthy gains in recent years, including in the legislative and congressional districts drawn by the last Independent Redistricting Commission in 2011. Five of the state's nine congressional districts are represented by Democrats. And though Republicans still control both legislative chambers, they hold only one-vote majorities in both the House of Representatives and the Senate, their smallest majorities since the GOP took control from the Democrats in the 1966 election.

However, the population growth trends over the last decade indicate that, when the current Arizona Independent Redistricting Commission draws its new lines, it's the Republicans who stand to make the most gains.

Based on the population numbers from the 2020 census, each new congressional district will have an average of about 794,000 people, and each legislative district will average about 238,000. Congressional districts must have almost the exact same number of people. But with legislative districts, the Supreme Court has granted a bit more leeway, allowing deviations of 5% above or below average, as long as those population differences were created for reasons the court deems valid.

The AIRC doesn't just alter the preexisting lines to equal out district populations. It wipes the map clean, then draws new districts based on a set of six criteria in the Arizona Constitution.

Nonetheless, population numbers in the new districts can be instructive.

Big growth in deep red districts

Republicans hold at least two of the three seats in 16 of Arizona's 30 legislative districts. Twelve of those 16 districts are overpopulated. In the 14 districts where Democrats hold the majority of seats, only three are overpopulated.

That means the new residents in heavily Republican growth areas will have to be spread out among more legislative districts. That makes it likely that more districts will favor the GOP, and more voters in conservative areas will be drawn into areas that are currently more politically competitive, said Republican consultant Nathan Sproul.

"Even though Republicans haven't seen a huge increase in their numbers as compared to the Democrat numbers, once the districts are evened back out, it will have a disproportionate benefit to Republicans," said Sproul, who led the Arizona Republican Party's redistricting efforts at the first AIRC in 2001.

Some of the overpopulated Republican districts are tens of thousands of people over the average district size, according to Dave's Redistricting, a website that uses census data and mapping software to allow people to draw their own districts.

The most overpopulated district is Gilbert-based District 12, which is more than 70,000 people above average. Nearby District 16, which includes East Mesa, Apache Junction and nearby parts of Pinal County, is overpopulated by 33,000 people. On the other side of the Phoenix metro area, District 13, which stretches from northern Yuma to the fast-growing suburbs of the West Valley, is 46,000 people above average. And District 22, which takes in parts of Peoria, Surprise and Sun City, is overpopulated by about 38,000.

Those numbers reflect the massive population growth in the suburban Valley. Queen Creek, which is in District 12, more than doubled in population over the past decade to about 59,000 people. Gilbert added more than 59,000, a 28.5% increase. Goodyear, situated in District 13, grew by 46%, adding 30,000 residents. Buckeye, split between District 13 and a neighboring Democratic district, gained nearly 41,000 people, a nearly 80% increase.

Meanwhile, some Democratic districts face significant population deficits. District 7, a predominantly tribal district that covers the Navajo Nation and runs south to the San Carlos Apache Reservation, is underpopulated by nearly 41,000 people, by far the biggest deficit in the state. Districts 2, 3 and 4, all based in southern Arizona, have deficits of 17,000, 27,000 and 12,000, respectively. Two other southern Arizona districts controlled by Democrats, Tucson-based Districts 9 and 10, are each underpopulated by nearly 15,000 people.

Legislative districts don't have to have exactly equal populations. But Sproul noted that Democratic districts are often underpopulated by design in order to ensure that the map complies with the Voting Rights Act by giving minority voters districts where they can elect the candidates of their choice. That makes it difficult to move Republican voters into those districts or Democratic voters out of them in order to make other districts more competitive.

"That has to stand. Every 10 years, weird alliances form between Republicans and Hispanic Democrats," Sproul said.

Population growth doesn't tell the whole story

D.J. Quinlan, a political consultant who headed up the Arizona Democratic Party's redistricting efforts in 2011, said things may be better for Democrats than the population numbers suggest.

Indeed, the heaviest growth has been in heavily Republican areas. But the fact that an area is historically conservative doesn't necessarily mean everyone who moves there is a Republican, Quinlan said. The state is getting more diverse, with growing Latino and Black populations. And young people looking to buy homes gravitate toward more affordable areas in the suburbs and exurbs, he said, changing their political makeup.

"The growth doesn't necessarily take on the characteristic of what was there previously," Quinlan said.

Quinlan pointed to Chandler and Ahwatukee, two Republican areas that have become more favorable to Democrats since the current districts went into use.

Chandler-based District 17, which is overpopulated by 24,000, has become a genuine swing district. Though still predominantly Republican, the district has elected Democrat Jennifer Pawlik to the House in each of the past two elections. The GOP's voter registration advantage in the district was nearly 13 percentage points in 2012, the first election in which it was used. Today, the difference is under 6 percentage points.

And District 18, which takes in Ahwatukee and western Chandler, went from all Republican to all Democrat over the past decade. Democrats went from having a 7-point deficit to a nearly 2-point advantage.

Districts 17 and 18 both voted for Biden in November. District 17, where Biden won a narrow victory by 3.7 percentage points, was the only legislative district with a Republican representative vote for the Democratic candidate for president, according to an analysis by Republican consultant Paul Bentz.

Quinlan noted that Democrats' improved performance in Arizona elections over the past few years wasn't restricted to individual legislative districts. The state as a whole, along with Maricopa County, have become more favorable to Democrats in general since the last census.

The GOP's voter registration advantage statewide shrank from more than 5 percentage points to a shade under 3 points. In Maricopa County, which now has nearly 62% of the state's population — up from nearly 60% in 2010 — the Republican edge shrank from nearly 9 points to about 3.5 points.

The last three general elections have reflected that trend. In 2016, voters elected Democrats as Maricopa County's sheriff and recorder, the first time in 18 years that Democrats won a countywide race there. In 2018, Democrats won statewide races for secretary of state, superintendent of public instruction, a Corporation Commission seat and a U.S. Senate seat. Last year, Joe Biden became the first Democratic presidential candidate to win Arizona since 1996, and only the second since 1948, while the election of Mark Kelly gave Arizona an all-Democratic U.S. Senate delegation for the first time since 1952.

"While the census is only every 10 years, elections happen every two years, and in general what we've seen in a lot of these same suburbs that are growing is also a shift in Democratic performance. And that's been really happening across the Valley, including in areas that were once thought of as Republican bastions," Quinlan said.

That doesn't mean things will get better for Democrats in Arizona's legislative map. Lines can be drawn to unfairly benefit a particular party, and Republicans have long alleged that the 2011 redistricting commission did just that. The commission's independent chair sided with her two Democratic colleagues on most key votes, giving them effective control of the five-person body.

Sproul said the last commission drew districts that advantaged the Democrats, and that their 29 House seats and 14 Senate seats represent a "high-water mark..

"I tip my hat to the Democrats 10 years ago, because they drew absolutely the best map they could've gotten. And now, they clearly don't have the same advantage this time," Sproul said.

And voter registration numbers in the heaviest growth areas haven't changed much in Democrats' favor. Outside of District 17, where Democrats have made concrete gains, most of those areas are as red as they were in 2012, when the current map went into effect. District 13's partisan composition hasn't changed as its population grew. Districts 16 and 22 actually got slightly more Republican.

Only in District 12 did Democrats make gains vis-a-vis the GOP, whose voter registration advantage shrank from 29 percentage points to 22 points.

Though Democrats have become more competitive in Maricopa and, as a result, statewide, their growth has been concentrated, which makes it difficult to translate into increased legislative power. Most of the Democratic growth has been within the boundaries of Loop 101, Bentz said, while the heaviest population growth has been outside of it.

"Look at the map of voting behavior sort of outside the central corridor, and it is still very dark red," Bentz said.