In it, but not of it. TPM DC
As a key matter, this was the first race for federal office in California to be held since voters approved a major change to the electoral system. Indeed, it was widely expected that that Hahn and Bowen would advance to a runoff, making a potential "win" by Huey for second place something of an upset.
In a referendum held during last year's primary, California's voters approved Proposition 14, which replaced the conventional party primaries with a different system known as Top Two, which has already been in use in Washington state for the past few years. (A similar system has been used for a long time in Louisiana, sometimes called the "jungle primary," but Washington state's version was the model used for California -- and in fact, Louisiana has scrapped the use of the jungle primary for federal races.)
Under this system, which took effect in January this year, all candidates will appear on the same ballot, with their respective party labels next to their names, and the top two voter-getters advancing to the general election. This system allows for the possibility of two Democrats or two Republicans facing off in very safe districts, which is thought to benefit more moderate candidates, though in statewide races and swing districts there will likely be one Dem vs. one GOPer.