This doesn't apply to Presidential elections, only to U.S. Senate seats from AZ and the Arizona governorship, which are usually the highest level Arizona-based offices on a ballot in AZ.
It's also not a partisan thing as both Ds and Rs fall on both sides of this.
Lastly, when I say "no experience in lower-level offices", I'm not talking about school board or city/town council seats (with one exception) - I didn't look that far into the background of any candidate.
It's not absolutely true - people with experience in lower-level elected offices have lost races for higher office*, and at least one person with no experience in elected office has won a top-of-the ballot race.
* = usually they ran against incumbents or other people with experience in lower-level elected offices.
In the following list, an asterisk (*) next to a candidate's name means that candidate won the race.
"Nada" means that neither office was on the ballot. I believe that the next time that will happen is 2032..
The races (I started in 1994 because I moved here in 1993) -
Twice, Kari Lake has run for office (2024 [Senate] and 2022 [Governor]), and twice she has lost.
She's not running for governor again, but the two main candidates in the R primary for that office in 2026 exhibit some of the same weaknesses as her.
Andy Biggs, former legislator and current Congressman, is disliked by most people who meet him. As is Lake.
Karrin Taylor Robson is a rich/famous person looking to buy an elected office. As was Lake.
Cheeto has famously endorsed both, which may help them in a Republican primary.
However, given his monetization of public service for himself (and his allies) and his cratering of it for everyone else (ya know, the public), that endorsement may not help in a general election (I'm presuming that one of them will win the primary).
In 2022, D Mark Kelly defeated R Blake Masters for US Senate. Masters was widely seen as a carpetbagger serving as a rich guy's tool/proxy and had never been in elected office.
In 2020, D Mark Kelly defeated R Martha McSally for a US Senate seat. While Kelly had no experience in public office and McSally was a member of Congress, he was retired from the military and could pick the brain of his wife, former member of Congress and state legislator, Gabby Giffords. Those things seem to have helped him.
In 2014 and 2018, R Doug Ducey defeated both Ds David Garcia and Fred Duval in their runs for governor. In 2018, Ducey was an incumbent; in 2014,he may not have been an incumbent, but had one term as state treasurer under his belt. While Garcia and Duval had stretches in public life, neither had been in elected office.
In 2012, R Jeff Flake defeated D Richard Carmona for US Senate. Carmona had public service behind him, but Flake was a member of Congress.
In 2010, R Jan Brewer defeated D Terry Goddard for governor. While he had been in elected office before and she was an unelected incumbent as Governor. However, she had been Secretary of State and in the state legislature.
In 2010, R John McCain defeated D Rodney Glassman. While Glassman had previously been part of the Tucson City Council, McCain was an incumbent.
Glassman changed his party registration (many years ago) and, in 2026, will be running for state Attorney General as a Republican.
Glassman may be able to run as a uniter - the one thing that activists in both major parties can agree on is that most of them dislike him.
In 2006, R Jon Kyl defeated D Jim Pederson for US Senate. Kyl was an incumbent; Pederson had never been in office.
In 2006, D Janet Napolitano defeated R Len Munsil. She was an incumbent; he had never been in office.
In 2004, R John McCain defeated D Stuart Starky for US Senate. McCain was an incumbent, and, to the best of my knowledge, Starky has never been in office.
2004 was before I became politically active, so my knowledge is spotty.
In 2002, D Janet Napolitano defeated R Matt Salmon. At that point, he was a member of Congress but she had run statewide and been Attorney General.
In 1998, R John McCain defeated D Ed Ranger for US Senate. McCain was an incumbent, and, to the best of my knowledge, Ranger has never been in office.
In 1998, R Jane Hull defeated D Paul Johnson. While he had been mayor of Phoenix, she was an unelected incumbent who had been Secretary of State and in the state legislature.
In 1994, R Jon Kyl defeated D Sam Coppersmith for US Senate. Kyl was an incumbent; Coppersmith had never been in office (so far as I know).
In 1994, R Fife Symington defeated D Eddie Basha for governor. Symington was an incumbent; Basha was a grocery magnate.
In short, the vast majority of races hold true to the title of this post, with a couple of noted exceptions.