Mayors in all of Texas, S.F. and Los Angeles are non-partisan elections. What about San Diego, is it an openly partisan election? Or is it just at Faulconer calls himslef “Republican”. I don’t know if they have party registration in CA any more, but they once did.
San Diego municipal elections are officially non-partisan (all Cali municipal elections are by state law I believe) but no one is shy about what party they are in. All it really means to have a non-partisan election that the party name doesn’t appear on the ballot and primary is a non-partisan affair where the top-2 advance (unless someone wins a majority) it doesn’t mean the candidates aren’t members of parties.
CA does still have registration by party.