“Arizona has not voted for a Democratic presidential candidate in 24 years, and the state has not been represented by two Democratic senators in over 65 years. So we find ourselves in a historically strange place: Joe Biden holds a small but consistent edge over the president, and Mark Kelly, the Democratic Senate candidate, holds a lead in his race against his Republican opponent, Martha McSally.
Why is Arizona suddenly a swing state?
The answer is frequently attributed to changes in the demographics of our electorate. It is true that Arizona’s population is increasingly urban, college-educated and Latino — trends that favor the Democratic Party.
But this influx of Democratic-leaning groups doesn’t explain the change. After all, the proportions of registered Republicans and Democrats in Arizona have remained remarkably stable: Registered Republicans solidly outnumber registered Democrats.
What has changed is that more Republicans aren’t voting for the party’s candidate in elections for national office.”