Must-read San Diego Union-Tribune article on gaming the top-two primary: “Democratic state Sen. Juan Vargas used some of the $630,000 he spent running for Congress in the primary election on an unusual but ultimately fruitful cause — direct mailers promoting a Republican rival, his preferred opponent in November. Vargas finished with 45 percent of the vote, according to unofficial results of Tuesday’s primary. Republican Michael Crimmins had 20 percent and former Democratic legislator Denise Moreno Ducheny had 15 percent.”

UPDATE: Richard Winger provides some important context.