Moorlach hasn't represented any part of this district in his entire time as supervisor. That isn't usually a big deal for voters, many of whom have no idea who their supervisor is.
Fleischman also links to a poll of the district race. The poll includes an option with Ed Royce, the congressman from a nearby district. Royce isn't running in this district. He's running in CA-39. He's already endorsed Mimi Walters in the race.
The polls show that Walters could do well, but the GOP has a lock on the district. The district does have a 16% Republican registration advantage. So that's understandable. And no, Gary Miller isn't running here, despite the rumors.