The Center for American Progress reports [thinkprogress.org]
As FiveThirtyEight's Nate Silver noted [fivethirtyeight.com] [the day after the election], Arizona's Eighth District has long been "extremely Republican". In 2016, President Donald Trump won it by a margin of 20 points; in 2012, Mitt Romney did even better, winning the district by 25 percentage points. Past elections have yielded similar results: during the 2008 presidential election, John McCain won the district by 22 points, despite winning the state by a smaller margin of 8.5 percentage points [realclearpolitics.com] overall.
[...][Republican congressional candidate Debbie] Lesko won the reliably red district with approximately 52.6 percent of the total vote [nytimes.com]--far lower than the 63-75 percent [her predecessor Trent] Franks had received in his past blowout wins.