I don't trust AZ at all. I think people are getting ahead of themselves on this one.
America’s sheriff got blown the out by 13 points in 2016. Even outside of Maricopa County, Arizona Dems ran ahead of the rot of Hillary Clinton—look at O’Halleran winning a Trump seat by 8 points.
Tbf O'Halleran's seat is ancestrally a blue dog Democrat seat. But given that most pollsters do not poll in Spanish, it would not surprise me if Sinema outperformed.
"Blue dog" is a really bad descriptor for that seat. It contains a lot of unusual demographic groups (Native Americans, including multiple rival tribal groups, small resort-town liberals in Sedona and Flagstaff, super-religious Mormons in Snowflake/Taylor/Holbrook etc. (not actual FLDS, who are outside the district, but more conservative than your average Utah Mormon)), which don't necessarily follow national trendlines, but that doesn't make it "blue dog".
Babeu I am certain underperformed because he is gay, especially in ultra-Mormon country. Navajo County, which is the center of the Mormon population in the district, voted for O'Halleran despite voting for Trump by 11% and had by far the biggest difference between Presidential and Congressional votes.
Babeu was going to loose but he ended up loosing by a large margin because of all his scandals, not because he is gay. Though, one of his scandals includes threatening to deport his immigrant lover if he outed him as gay.
O'Halleran is a good independent minded(former GOP state rep) which helped his case.
I also believe mormons in the white mountain region are more likely to vote for democrats than mormons in Provo or Mesa. The White mountain region itself does have many rural whites that are more wiling to vote for Democrats than rural whites in other regions - think of it as Montana in a way, still leans conservative but willing to vote D down ballot.
to go further on the last point, while Clinton lost Navajo county by 10 points, Kirkpatrick only lost by 2.8 and it was one of her best performing counties(she did so much better in this region than Clinton despite underperforming Clinton in Maricopa), and O'Halleran won Navajo.
Meanwhile in western Arizona counties like Yavapai and Mojave, rural whites aren't willing to vote Dem down ballot.
