One particularly good result for the Democrats' very good 2018 election was capturing a Senate seat in Arizona. Sinema won by 2.4 points in a state that Hillary Clinton lost by 3. 5 points in 2016, raising the possibility that Democrats might be able to carry the state in the 2020 Presidential election.
So how'd Sinema do it when Clinton couldn't? Once again the folks at Catalist Analytics have released some detailed data that help us answer that question. Their data for Arizona, built up from survey data, voter files and actual election returns, indicate relatively strong nonwhite turnout (the Catalist data do not break out nonwhites by black, Hispanic, etc) which helped keep the Arizona midterm electorate closer to the Presidential than is normally the case.
That was helpful for Sinema's cause but by far the biggest factor was strong shifts toward the Democrats in the white vote (75 percent of Arizona voters in 2018). Compared to 2016, Arizona whites shifted toward the Democrats by 11 margin points. That included a pro-Democratic shift of 13 points among white college voters (Sinema came close to breaking even with these voters) and an also-impressive shift of 10 points among noncollege whites. There were also big shifts among whites by age groups, with actually carrying all whites under 45.
The spatial dimension is also interesting. Sinema cleaned up in urban areas but also managed to narrowly carry suburban areas where two-thirds of Arizona voters reside (think especially Maricopa county). This was driven primarily by whites in suburban areas swinging a solid 11 points toward the Democrats.
Based on these patterns, Arizona should definitely be in play in 2020. For more information, consult the Catalist writeup below which, while murky, does contain a lot of nice tables.