Much of the post-2020 election discourse has centered on the Rust Belt or on Georgia, but the closest state in terms of raw vote totals was Arizona. By a margin just shy of 10,500 votes, Joe Biden became just one of two Democrats to carry the state – home to conservative icons Barry Goldwater and John McCain, who were also presidential nominees in their own right – in a presidential election since the 1940s. The other was Bill Clinton in 1996, who may have benefited from a strong third party challenge by Ross Perot, who received 8% in the state that year. Clinton also holds the distinction of being the only presidential candidate to win the state without winning Maricopa County, the state’s most populous. 2020 was a very, very different year.

Now, Maricopa County, home to Phoenix (the state’s largest city; it is also the nation’s fifth largest, or tenth largest metro) and about 60% of the state’s voters, is the clear political center of the state. A year ago, we described Phoenix as to Democrats in the Trump era what Denver was to the party in the Obama era: the “right city at the right time.” Like Las Vegas or Atlanta – other swing state Sun Belt metropolises which contain the majority of voters in their respective states – Phoenix packs an electoral punch that is hard for either party to ignore. And for now, Democrats seem to be winning. Like many Sun Belt cities, Phoenix has experienced high levels of growth in the last four years. Since 2020, around 330,000 people have moved to the state, largely concentrated in Phoenix suburbs like Gilbert, Chandler, Glendale, and Mesa. As the suburbs become more Democratic (particularly the Phoenix suburbs, which used to be more purple or red), we expect this to pad Democratic numbers slightly. It seems very likely that, were it not for around 250,000 people moving to the state from 2016-2020, Biden would have lost it in 2020.

Where Democrats will struggle is that, even as this part of their coalition grows, others are fraying. Latino voters (largely Mexican-Americans) seem to be moving rightward. Given that this bloc makes up nearly 30% of the state, Democrats will need to do everything possible to stop this shift or make up for it elsewhere. The problem is, they’re hitting something of a ceiling on the latter. Though Republicans have done very little to help themselves in the state – embracing increasingly extreme and conspiracy-minded positions, especially regarding election security and integrity, all major turn offs for moderate voters – there are diminishing marginal returns to how far consolidation of anti-Trump Republicans can go. Arizona took a big leap leftward in 2016 because of Trump (though he still won the state) – moving about 7.3 points towards Democrats compared to 2012; then in 2020 it moved about 1.5 points towards Democrats compared to 2016. It begs the question: how many Arizona Republicans voted for Trump in 2016, again in 2020, but have suddenly changed their mind for 2024? Some, for sure, but probably relatively few compared to the shifts of the last two presidential cycles.

So, let’s go back to the former. Perhaps more than any other swing state, immigration and the border will matter in Arizona. These are issues which Republicans very clearly poll better on, especially at the presidential level, and this is a clear problem for Harris in a state which has the second-largest border with Mexico. This is alienating not just stereotypically anti-immigration Trump voters, but also Latino voters, who are more likely to suffer from increased labor market competition due to illegal immigration. With the largest proportion of Latino voters of any swing state, whatever happens to this demographic’s vote intention this cycle will hit hard in Arizona and seems likely to meaningfully affect the outcome – and it’s not just immigration where Democrats are vulnerable. Latino voters in the state are also starting to trust Republicans more on economic issues. Though, in the state’s Senate race, Latinos seem inclined to vote for the Democrat by about the same margin as they gave Biden in 2020 (around 63%), Harris is doing a bit worse – if still outperforming Trump.

The economic reasons extend beyond the state’s Latino population. Though the state has done relatively well over the last few years and enjoyed plenty of federal investment as part of the Biden administration’s programs, higher house prices and economic anxiety have percolated through the electorate. All of that growth and migration has put pressure on prices, harming those – like Latino voters – who are younger, have lower incomes, and are more likely to rent.

For all the Democratic dooming, there’s reason to think that Arizona remains clearly in play (if requiring a mid-sized national overperformance by Harris). Like many states, the Grand Canyon state will feature an abortion ballot measure this year which aims to protect abortion until the point of fetal viability. Though there’s good reason to be skeptical that abortion ballot measures like this will be a significant driver of turnout for Democrats, Arizona has been in the spotlight on the issue, especially after pro-choice advocates were riled up by the state’s flirtation with an outright ban earlier this year. Arizona’s small government streak seems poised to deliver a pro-choice victory there. Democrats have also put a lot of effort into organizing both up and down the ballot in the last four years, and it shows: with both Houses of the Arizona Legislature up for grabs this cycle, Arizona has been the focus of increased Democratic organizing efforts that also figure to benefit Democrats up ballot. There’s precedent for focused organizing to make a difference too: Native Americans make up about 6% of Arizona’s population and are of recent electoral import (Biden would not have won the state in 2020 without them), so any continued efforts at organizing or driving left-leaning Natives to the polls will help Harris a tad. And – as the swing state with the highest share of the population enrolled in college – any boost in youth turnout, or new registrations in Arizona (something that may not have happened in 2020, given that colleges sent students home during COVID-19) will likely pad Harris’ base of support.

There are still some clear red flags for Harris: even as the population has grown, the number of registered Democrats in the state has dropped by nearly 200,000, while registered Republicans are down about 75,000 (independents are up about 37,000). This isn’t as dire as it may seem: Republicans had a registration advantage in 2022 and still went down in that year’s Senate and gubernatorial elections by about five points and one point, respectively. Arizona is also an open primary state, so there’s no particular advantage to explicitly registering to be a member of one party or another. Still, the “blue bleed” may be indicative of enthusiasm problems (potentially a remnant of the Biden malaise) or some self-sorting migration to the state (think of the tax-saddled conservatives in California looking to move – but not move too far!), so some caution for Democrats is warranted. There’s also been some dispute about whether recent voting law changes, passed in 2022, challenged, and recently partially upheld, will affect the vote in the state, but the net impact appears to be negligible.

Where does this all leave the Copper State? Depending on the national environment, still quite close. Trump will benefit from passionate supporters and potentially some shift to his coalition by Latinos; Harris could reap rewards from the far-right’s recent toxicity in the state and the state’s influx of new voters. Yet again, Arizona could very well could come down to just a few thousand votes. That’s exactly the kind of election where a slight increase in a tiny fraction of a local demographic, a key celebrity endorsement, or organizing strength could make the difference – exactly what we wanted to showcase with our approach and our model this year. We’ve put a lot of thought into Arizona and landed where we are: any tiny shift could change the outcome.