PHOENIX — President Biden is the first Democratic candidate to win Arizona’s electoral college votes since Bill Clinton’s second run in 1996.
His victory over Trump is the narrowest in the state’s history. You must go back to Calvin Coolidge’s win over John Davis in 1924 to find a raw vote victory closer than 10,457, and that was a time when only 56,751 votes were cast in a presidential race.
So how did he pull out a victory in a state that simply does not have a recent history of supporting Democratic presidential candidates? Simply put, amidst a massive turnout swell in both parties, a small, mostly suburban, group of voters changed their minds about former President Donald Trump.
When you look at the data, here is how it broke down.
Every state has voting precincts where most voters always support the Presidential candidate of one party or another. For Democrats, these precincts are clustered in dense urban areas that are typically more ethnically diverse and have a median household income that ranges from very low to very high.
For Republicans, these precincts are rural or exurban enclaves on the outskirts of a metro area. They are mostly comprised of white voters and the median household income is more dependent upon if the precinct is exurban or rural.
These are called base precincts and Republicans have more of them in Arizona. Most voters in 751 precincts supported Trump both in 2016 and 2020. These President Trump base precincts accounted for 1,868,428 of the total vote-share in the Presidential contest. President Biden, meanwhile, received the majority of the votes in 635 precincts, which were worth 1,256,916 votes to all of the candidates combined.
President Trump was more reliant on base precincts than Biden. 68%, or 1,130,703, Trump votes came from base precincts. This is compared to the less than 50%, or 830,225, that Biden received from Democratic base precincts. Trump even increased his vote total in base precincts more than Biden; 285,868 more voters in Republican base precincts supported Trump in 2020 compared to 229,308 more voters for Biden in Democratic base precincts.
58% of Arizona’s total presidential vote came from base precincts.
While base precincts provide each candidate with most of their votes, a substantial share of votes also come from their opponent’s base.
Due to the larger raw total vote share in Republican base precincts, Democrats tend to do well in this category, but Biden did exceptionally well. Biden received 705,682, or 42%, of his final vote count from precincts that supported President Trump in both 2016 and 2020. Less than a quarter of Trump’s total votes, 405,866, came from traditionally Democratic precincts.
Both candidates’ totals were higher in opposition precincts than what they were in 2020, but President Biden added 238,047 more votes in this category than Hillary Clinton received in 2016, a 50% increase. Trump was only able to add 99,556 votes from opposition precincts in 2020.
33% of the total presidential vote comes from opposition precincts.
If you add up the numbers above, you will notice something interesting. When accounting only for solidly Republican or Democratic precincts, President Trump is winning 1,536,569 votes to President Biden’s 1,535,907. A difference of 622.
Biden won the election in Arizona by 10,457, so the difference is found in the precincts that flipped their support to a different political party’s candidate between 2016 and 2020. Trump was only able to take 5 precincts away in 2020 that Clinton won in 2016. These precincts were only worth 1,773 votes in total for both candidates.
Joe Biden is another story. He successfully flipped 98 precincts in Arizona that Trump won in 2016, collectively worth 258,177 votes. Every single one of them supported Kyrsten Sinema in her win against Marth McSally in 2018. The precincts are nearly all in suburban Maricopa and Pima counties, with the Maricopa precincts situated around the Loop 101 Freeway. President Biden won these 132,579 to 121,331, a difference of 11,248 votes.
These precincts are only worth 8% of the total presidential vote share but proved to be critical to the outcome. With turnout equally surging for both President Biden and President Trump, it was this small slice of suburbia in Arizona that delivered the state’s 11 electoral votes to Joe Biden.