This reverse triangulation (which has also been pointed out by Sean Trende and Kyle Kondik) means that Flake gets the worst of both worlds. He loses some staunch Trumpish voters by attacking the president and taking a few unorthodox positions, but votes too conservatively on the whole to bring in many Democratic crossover votes.
This isn’t just a theoretical problem for Flake — it shows up in elections and polling. In 2012, Romney won the state by nine points while Flake won his Senate race by only three. I used an RCP Senate model to check if Democrat Richard Carmona was responsible for the difference, and found that he performed almost exactly as we would expect a Democratic non-incumbent to, given Obama’s approval rating at the time. Flake, on the other hand, won 49.2 percent of the vote while Romney won 53.5 percent, and earned 129,127 fewer total votes than Romney while Carmona actually earned 11,310 more than Obama.
In other words, Flake underperformed one of the most generic Republican presidential candidates in recent memory by a modest but real margin.