Late on April 8, in the headquarters of the Republican Party of San Diego County, Carl DeMaio had three negotiators representing him. He had just failed to get the party’s Central Committee to endorse his run for State Assembly even though it had already endorsed his opponent. The whole episode had left his ally, then party chair Paula Whitsell, vulnerable to losing her position.One of his negotiators was Corey Gustafson. Gustafson is now the pa…