In 2004, President Bush won Arizona by a margin of 10.5% over John Kerry. In 2008, John McCain beat President-elect Obama by 8.5%. Bush won 1,104,294 votes to Kerry's 893,524 - a margin of 210,770 votes. McCain won 1,230,111 to 1,034,707 for Obama - winning by 195,404. Despite a 14% increase in turnout (raw votes, not rate), the Republican margin shrank by 15,366 votes.
I took that margin change and spread it over each county, weighted for the counties' vote shares from 2008. If the margin change was spread proportionately, each county would be responsible for the changes listed below. The actual changes are listed in parentheses.
Maricopa 9,145 (30,324)
Pima 2,636 (1,829)
Pinal 703 (-5,413)
Yavapai 668 (-3,962)
Mohave 453 (-5,950)
Coconino 364 (2,530)
Cochise 327 (-1,041)
Yuma 292 (134)
Navajo 240 (-1,720)
Apache 163 (-435)
Gila 150 (-2,182)
Santa Cruz 89 (1,924)
Graham 80 (-607)
La Paz 37 (-271)
Greenlee 20 (206)
I started looking into the counties that had large disparities from their projected proportional shifts to see what we could learn from them.
First, Maricopa County was responsible not for 60% of 15,366 margin change that it "should" have been. Instead, the Republican margin in Maricopa County actually shrunk by 30,324, nearly twice the statewide change. Why? Bush beat Kerry 57.0%-42.3% - a margin of 14.7%. McCain beat Obama 54.7%-44.1% - a margin of 10.6%. That's the power of Maricopa County: such a small percentarge shift turns into 30k+ votes. The good news for future Tim Nelsons, Dan Sabans, and Ed Hermeses is that the GOP's margin in 'Copa shrank by 4.1%, while in Arizona overall it only shrank by 2%. Between 2004 and 2008, Maricopa blued faster than the rest of the state. Maybe that explains our recent wins in LDs 10, 11, and 20.
The next question is: which counties offset Maricopa's blueing and helped the Republicans only lost 2% off of their statewide margin?
Obviously, I'm going to blame Pima County. Obama did no better than Kerry here, winning by the same 6% margin (Kerry won 52.6%-46.6%; Obama won 52.4%-46.4%). And their vote total grew by only 7.2%, compared to 14% statewide. Thus, the Republican margin in Pima shrank by only 1,829 votes, far below the "projected" 2,636. Now, I can't really blame Pima. They didn't contribute to the state's 2-point shift, but they didn't pull against it, either.
The real culprits are Pinal, Yavapai, Mohave, Navajo, and Gila counties. They will be dealt with in ascending order of their degree of treason against the Maricopa County proletarian revolution.
Navajo County gets off lightly. They only delivered McCain a margin 1,720 votes larger than they gave Bush. Their registration numbers were virtually unchanged from 2004 - only a 1.4% increase compared to 13% statewide. The turnout rate jumped from 56% to 61.2%, but was still far below the 76.8% statewide. Yet, they did manage to buck the blueing trend of the country and the state and voted 55.2%-43.5% for McCain, whereas they'd only voted 53.4%-45.8% for Bush.
Gila County's crime is only a little graver than Navajo's, but is more treacherous because of they managed it with only 2/3 the voters of Navajo. Gila pushed McCain's margin 2,182 over Bush's. They did this despite turnout falling from 77.9% to 71.7%. Registration jumped by 16.3%, a little more than the statewide increase. But the real source of their treason is a dramatic shift to the right: voting 63.1%-35.3% for McCain compared to 59.2%-39.9% for Bush.
Yavapai County did have have as malicious an intent as the others. They voted for McCain, 61.4%-37.0%, only slightly worse than Bush's 61.2%-37.9%. However, their size makes their crime more significant. Turnout dropped from an astronomical 87.5% to 83.8% (which is still the highest in the state), but registration jumped 19.1%. As a result, they gave McCain a margin of 3,962 higher than Bush's.
Pinal County is a similar story, but even worse for their size and growth. Their 2008 vote, 56.7%-42.2% for McCain, is nearly the same as their 57.3%-42.2% vote for Bush. The turnout rate increased, but only barely. Instead, their weapon of betrayal was their remarkable 60% (!) jump in registration (since 2000, it's a 97% increase!). As a result, they gave McCain a margin 5,413 greater than Bush's. It would take 3 times Pima County's marginal increase for Obama to match Pinal County's marginal increase for McCain.
Only Mohave County gave McCain a greater increase over Bush's margin than Pinal County. Their registration increased 10.7%, their turnout jumped from 60.8% to 64.3% and they gave McCain a higher vote share than Bush by two points. Bush won by 63.6%-35.5%, while McCain won by 65.6%-32.7%.
Beyond these criminal 5, which gave McCain a combined margin 19,227 higher than Bush's, Santa Cruz, Cochise, Coconino, and Yuma are interesting.
Santa Cruz had only a 2.4% registration increase, low turnout (despite a jump from 56.1% to 62.5%), and is obviously very small. But they shifted dramatically to the left, voting 65.3%-34.0% for Obama, after voting 59.2%-40.0% for Kerry. That marks the largest percentage swing in either direction in the entire state. Thus, despite its small size, it gave Obama a margin 1,924 greater than Kerry's.
Coconino managed to give Obama a larger margin, by 2,530 votes, despite a 2.9% decrease in registered voters. They did that with a 5-point jump in turnout, a 4.2% increase in Obama's margin. Cochise is noteworthy because of its 18.8% registration increase. That increase gave McCain a 1,041 vote bump despite a turnout 6-point turnout drop and no change in the McCain-Bush vote shares. Finally, Yuma showed the second-highest registration increase by percentage, at 25.1%. They also say a dramatic turnout drop (about 7 points) and experienced about a 2-point partisan shift, exactly the statewide average (they still gave McCain 56.3% to Obama's 42.6%).